Transpedicular intervertebral disk access methods and devices

ABSTRACT

A flexible drill and method of drilling a material are disclosed. According to one embodiment, a flexible drill includes a lower sub-assembly connected to an upper sub-assembly, where the lower sub-assembly comprises a retainer tube and the upper sub-assembly comprises a guiding tube; a drilling tip, and capable of orienting the drilling tip at a predetermined position after accessing a material to he drilled through a substantially straight passage having a lone axis. The predetermined position is at least 10° off of the lone axis of the substantially straight passage. According to one embodiment, a method of drilling a material includes the steps of (a) providing a flexible drill; (b) advancing the drill through a substantially straight passage until the drilling tip accesses the material to be drilled, thereby orienting the drilling tip at the predetermined position; and (c) actuating the drill.

CROSS-REFERENCE TO RELATED APPLICATION

The present Application is a continuation of PCT patent applicationPCT/US03/09285, filed Mar. 25, 2003, Entitled “TranspedicularIntervertebral Disk Access Methods And Devices,” that claims the benefitof U.S. provisional patent application 60/424,942, filed Nov. 8, 2002,entitled “Transpedicular Intervertebral Body Fusion,” the contents ofwhich are incorporated herein by reference in their entirety.

BACKGROUND

The human vertebral bodies and intervertebral disks are subject to avariety of diseases and conditions that change the spacial relationshipbetween the vertebral bodies and the intervertebral disks, causing pain,disability or both. Many of these diseases and conditions also causeinstability of the vertebral column. Among these diseases and conditionsare degenerated, herniated, or degenerated and herniated intervertebraldisks, degenerative scoliosis, disk or vertebral body infections, spaceoccupying lesions such as malignancies, spinal stenosis, spondylosis,spondylolisthesis, and vertebral instability. Additionally, thevertebral bodies and intervertebral disks are subject to injuries,including vertebral fractures due to trauma or osteoporosis, and tosurgical manipulations, that change the spacial relationship between thevertebral bodies and the intervertebral disks, causing pain, disabilityor both, and that cause instability of the vertebral column.

Surgical treatment of diseases and conditions affecting the spacialrelationship between the vertebral bodies and the intervertebral diskshave traditionally involved open fusion procedures that include making alengthy incision through the tissues overlying the spinous processes,thereby directly accessing the vertebrae to mechanically fuse twoadjacent vertebrae. These procedures result in considerablepost-operative pain and a significant incidence of post-operativemorbidity, including infection. Further, traditional procedures do notallow the surgeon to directly access the intervertebral space to restorethe more normal three-dimensional configuration of the space.

Therefore, there is a need for a new method for treating diseases andconditions that changes the spacial relationship between two vertebralbodies and the intervertebral disk between the two vertebral bodies, orthat cause instability of the vertebral column, or both, that isassociated with less post-operative pain and a lower incidence ofpost-operative morbidity. Further, there is a need for a new method fortreating diseases and conditions that change the spacial relationshipbetween the vertebral bodies and the intervertebral disks, or that causeinstability of the vertebral column, or both, that allows the surgeon todirectly access the intervertebral space to mechanically fuse twoadjacent vertebrae.

SUMMARY

According to one embodiment of the present invention, there is provideda flexible drill comprising a drilling tip, and capable of orienting thedrilling tip at a predetermined position after accessing a material tobe drilled through a substantially straight passage having a long axis,where the predetermined position is at least 10° off of the long axis ofthe substantially straight passage. In one embodiment, the flexibledrill further comprises a lower sub-assembly connected to an uppersub-assembly, where the upper sub-assembly comprises the drilling tip.In another embodiment, the lower sub-assembly comprises a spin luerlock, a retainer tube, a piston anchor, a piston level, a piston, adistal O-ring and a proximal O-ring, and the upper sub-assembly furthercomprises a guiding tube, a barrel knob, a barrel, a threaded adapter, aliner, a bearing housing, a flexible shaft, a distal bearing, a proximalbearing, a collet, a bearing cap and a motor receptacle. In anotherembodiment, the upper sub-assembly comprises a guiding tube comprising aproximal segment having a central axis and a distal segment having adistal end, the drilling tip is connected to the distal end of thedistal segment; and the guiding tube comprises a substance that has beenprocessed to return to a shape such that the distal segment has a radiusof curvature sufficient to cause the drilling tip at the end of thedistal segment to orient at between about 10° and 150° off of thecentral axis of the proximal segment when the guiding tube is notsubject to distortion. In another embodiment, the upper sub-assemblycomprises a guiding tube comprising a proximal segment having a centralaxis and a distal segment having a distal end, the drilling tip isconnected to the distal end of the distal segment, and the guiding tubecomprises a substance that has been processed to return to a shape suchthat the predetermined position of the drilling tip is at least 10° offof the long axis of the substantially straight passage. In anotherembodiment, the flexible drill further comprises a guiding tubecomprising a proximal segment having a central axis and a distal segmenthaving a distal end, the drilling tip is connected to the distal end ofthe distal segment, and the guiding tube comprises a substance that hasbeen processed to return to a shape where the distal segment has aradius of curvature sufficient to cause the drilling tip at the end ofthe distal segment to orient at between about 10° and 150° off of thecentral axis of the proximal segment when the guiding tube is notsubject to distortion. In another embodiment, the flexible drill furthercomprises a guiding tube comprising a proximal segment having a centralaxis and a distal segment having a distal end, the drilling tip isconnected to the distal end of the distal segment, and the guiding tubecomprises a substance that has been processed to return to a shape suchthat the predetermined position of the drilling tip is at least 10° offof the long axis of the substantially straight passage. In anotherembodiment, the flexible drill further comprises a guiding tip attachedto the drilling tip. In another embodiment, the flexible drill furthercomprises an axial channel for accepting a guide wire.

According to another embodiment of the present invention, there isprovided a flexible drill comprising a guiding tube having a proximalsegment having a central axis and a distal segment having a distal end,and a drilling tip is connected to the distal end of the distal segment,the guiding tube comprises a substance that has been processed to returnto a shape where the distal segment has a radius of curvature sufficientto cause the drilling tip at the end of the distal segment to orient atbetween about 10° and 150° off of the central axis of the proximalsegment when the guiding tube is not subject to distortion. In oneembodiment, the flexible drill further comprises a guiding tip attachedto the drilling tip. In another embodiment, the flexible drill furthercomprises an axial channel for accepting a guide wire.

According to another embodiment of the present invention, there isprovided a flexible comprising a lower sub-assembly connected to anupper sub-assembly, the lower sub-assembly comprises a spin luer lock, aretainer tube, a piston anchor, a piston level, a piston, a distalO-ring and a proximal O-ring, and the upper sub-assembly comprises adrilling tip, guiding tube, a barrel knob, a barrel, a threaded adapter,a liner, a bearing housing, a flexible shaft, a distal bearing, aproximal bearing, a collet, a bearing cap and a motor receptacle, theguiding tube comprising a proximal segment having a central axis and adistal segment having a distal end, the drilling tip is connected to thedistal end of the distal segment, and the guiding tube comprises asubstance that has been processed to return to a shape where the distalsegment has a radius of curvature sufficient to cause the drilling tipat the end of the distal segment to orient at between about 10° and 150°off of the central axis of the proximal segment when the guiding tube isnot subject to distortion. In one embodiment, the flexible drill furthercomprises a guiding tip attached to the drilling tip. In anotherembodiment, the flexible drill further comprises an axial channel foraccepting a guide wire.

According to another embodiment of the present invention, there isprovided a method of drilling a material comprising a) providing aflexible drill according to the present invention, b) advancing thedrill through a substantially straight passage until the drilling tipaccesses the material to be drilled, thereby orienting the drilling tipat the predetermined position, and c) actuating the drill. In oneembodiment, the method further comprises passing a guide wire throughthe drill either before actuating the flexible drill, after actuatingthe flexible drill, or both before and after actuating the flexibledrill. In another embodiment, the material to be drilled is selectedfrom the group consisting of bone, cartilage and intervertebral disk. Inanother embodiment, the method further comprises inserting a sheath intothe substantially straight passage before inserting the flexible drilland then inserting the flexible drill through the sheath.

According to one embodiment of the present invention, there is provideda flexible drill comprising a drilling tip, and capable of orienting thedrilling tip at a predetermined position after accessing a material tobe drilled through a substantially straight passage having a long axis,where the predetermined position is at least 10° off of the long axis ofthe substantially straight passage. In one embodiment, the flexibledrill further comprises a lower sub-assembly connected to an uppersub-assembly, where the upper sub-assembly comprises the drilling tip.In another embodiment, the lower sub-assembly comprises a spin luerlock, a retainer tube, a piston anchor, a piston level, a piston, adistal O-ring and a proximal O-ring, and the upper sub-assembly furthercomprises a guiding tube, a barrel knob, a barrel, a threaded adapter, aliner, a bearing housing, a flexible shaft, a distal bearing, a proximalbearing, a collet, a bearing cap and a motor receptacle. In anotherembodiment, the upper sub-assembly comprises a guiding tube comprising aproximal segment having a central axis and a distal segment having adistal end, the drilling tip is connected to the distal end of thedistal segment; and the guiding tube comprises a substance that has beenprocessed to return to a shape such that the distal segment has a radiusof curvature sufficient to cause the drilling tip at the end of thedistal segment to orient at between about 10° and 150° off of thecentral axis of the proximal segment when the guiding tube is notsubject to distortion. In another embodiment, the upper sub-assemblycomprises a guiding tube comprising a proximal segment having a centralaxis and a distal segment having a distal end, the drilling tip isconnected to the distal end of the distal segment, and the guiding tubecomprises a substance that has been processed to return to a shape suchthat the predetermined position of the drilling tip is at least 10° offof the long axis of the substantially straight passage. In anotherembodiment, the flexible drill further comprises a guiding tubecomprising a proximal segment having a central axis and a distal segmenthaving a distal end, the drilling tip is connected to the distal end ofthe distal segment, and the guiding tube comprises a substance that hasbeen processed to return to a shape where the distal segment has aradius of curvature sufficient to cause the drilling tip at the end ofthe distal segment to orient at between about 10° and 150° off of thecentral axis of the proximal segment when the guiding tube is notsubject to distortion. In another embodiment, the flexible drill furthercomprises a guiding tube comprising a proximal segment having a centralaxis and a distal segment having a distal end, the drilling tip isconnected to the distal end of the distal segment, and the guiding tubecomprises a substance that has been processed to return to a shape suchthat the predetermined position of the drilling tip is at least 10° offof the long axis of the substantially straight passage. In anotherembodiment, the flexible drill further comprises a guiding tip attachedto the drilling tip. In another embodiment, the flexible drill furthercomprises an axial channel for accepting a guide wire.

According to another embodiment of the present invention, there isprovided a flexible drill comprising a guiding tube having a proximalsegment having a central axis and a distal segment having a distal end,and a drilling tip is connected to the distal end of the distal segment,the guiding tube comprises a substance that has been processed to returnto a shape where the distal segment has a radius of curvature sufficientto cause the drilling tip at the end of the distal segment to orient atbetween about 10° and 150° off of the central axis of the proximalsegment when the guiding tube is not subject to distortion. In oneembodiment, the flexible drill further comprises a guiding tip attachedto the drilling tip. In another embodiment, the flexible drill furthercomprises an axial channel for accepting a guide wire.

According to another embodiment of the present invention, there isprovided a flexible comprising a lower sub-assembly connected to anupper sub-assembly, the lower sub-assembly comprises a spin luer lock, aretainer tube, a piston anchor, a piston level, a piston, a distalO-ring and a proximal O-ring, and the upper sub-assembly comprises adrilling tip, guiding tube, a barrel knob, a barrel, a threaded adapter,a liner, a bearing housing, a flexible shaft, a distal bearing, aproximal bearing, a collet, a bearing cap and a motor receptacle, theguiding tube comprising a proximal segment having a central axis and adistal segment having a distal end, the drilling tip is connected to thedistal end of the distal segment, and the guiding tube comprises asubstance that has been processed to return to a shape where the distalsegment has a radius of curvature sufficient to cause the drilling tipat the end of the distal segment to orient at between about 10° and 150°off of the central axis of the proximal segment when the guiding tube isnot subject to distortion. In one embodiment, the flexible drill furthercomprises a guiding tip attached to the drilling tip. In anotherembodiment, the flexible drill further comprises an axial channel foraccepting a guide wire.

According to another embodiment of the present invention, there isprovided a method of drilling a material. The method comprises, a)providing a flexible drill according to the present invention, b)advancing the drill through a substantially straight passage until thedrilling tip accesses the material to be drilled, thereby orienting thedrilling tip at the predetermined position, and c) actuating the drill.In one embodiment, the method further comprises passing a guide wirethrough the drill either before actuating the flexible drill, afteractuating the flexible drill, or both before and after actuating theflexible drill. In another embodiment, the material to be drilled isselected from the group consisting of bone, cartilage and intervertebraldisk. In another embodiment, the method further comprises inserting asheath into the substantially straight passage before inserting theflexible drill and then inserting the flexible drill through the sheath.

According to another embodiment of the present invention, there isprovided a method of drilling a material, comprising a) providing adrill according to the present invention, b) advancing the flexibledrill under distortion into the material, c) removing the distortionfrom the flexible drill, d) actuating the flexible drill. In oneembodiment, the method further comprises passing a guide wire throughthe flexible drill either before actuating the flexible drill, afteractuating the flexible drill, or both before and after actuating theflexible drill. In another embodiment, the material to be drilled isselected from the group consisting of bone, cartilage and intervertebraldisk.

According to another embodiment of the present invention, there isprovided a cutting device comprising a blade connected to the distal endof a flexible shaft, where the cutting device can be inserted into amaterial to be cut after accessing the material through a channelcomprising a substantially straight proximal section having a long axisand a distal section having a long axis, and the long axis of the distalsection is curved, or where the long axis of the distal section issubstantially straight but varies at least about 10° off of the longaxis of the proximal section. In one embodiment, the blade pivots from afirst, insertion position to a second, cutting position. In anotherembodiment, the cutting device further comprises a locking sleevesurrounding at least part of the flexible shaft, the blade has one ormore than one notch, the locking sleeve can be advanced distally andretracted proximally, and advancement distally causes the locking sleeveto engage with the one or more than one notch, thereby locking the bladeinto the cutting position, and retraction proximally causes the lockingsleeve to disengage from the one or more than one notch, therebyunlocking the blade from the cutting position. In another embodiment,the cutting device further comprises a sheath having a beveled distalend and surrounding at least part of the flexible shaft, the flexibleshaft can be advanced distally and retracted proximally relative to thesheath, and retraction proximally of the flexible shaft causes the bladeto disengage from the locking sleeve and pivot to the insertionposition. In another embodiment, the blade has a circumferential cuttingedge. In another embodiment, the cutting device further comprises aproximal end comprising a motor adapter for connecting the cuttingdevice to a motor drive, and a distal end, where the blade is attached.

According to another embodiment of the present invention, there isprovided a cutting device comprising a) a pivoting blade connected tothe distal end of a flexible shaft, and b) a locking sleeve surroundingat least part of the flexible shaft, the blade pivots from a first,insertion position to a second, cutting position, where the blade hasone or more than one notch, where the locking sleeve can be advanceddistally and retracted proximally, and where advancement distally causesthe locking sleeve to engage with the one or more than one notch,thereby locking the blade into the cutting position, and retractionproximally causes the locking sleeve to disengage from the one or morethan one notch, thereby unlocking the blade from the cutting position.In one embodiment, the cutting device comprising further comprises asheath having a beveled distal end and surrounding at least part of theflexible shaft, where the flexible shaft can be advanced distally andretracted proximally relative to the sheath, and where retractionproximally of the flexible shaft causes the blade to disengage from thelocking sleeve and pivot to the insertion position. In one embodiment,the cutting device can be inserted into a material to be cut afteraccessing the material through a channel comprising a substantiallystraight proximal section having a long axis and a distal section havinga long axis, and the long axis of the distal section is curved, or wherethe long axis of the distal section is substantially straight but variesat least about 10° off of the long axis of the proximal section. Inanother embodiment, the blade has a circumferential cutting edge. Inanother embodiment, the cutting device further comprises a proximal endcomprising a motor adapter for connecting the cutting device to a motordrive, and a distal end, where the blade is attached.

According to another embodiment of the present invention, there isprovided a method of cutting a material comprising a) providing thecutting device of the present invention, b) inserting the cutting deviceinto the material after accessing the material through a channelcomprising a substantially straight proximal section having a long axisand a distal section having a long axis, and c) actuating the cuttingdevice, where the long axis of the distal section is curved, or wherethe long axis of the distal section is substantially straight but variesat least about 10° off of the long axis of the proximal section. In oneembodiment, the method further comprises advancing and retracting thecutting device withing the material. In another embodiment, the methodfurther comprises inserting a sheath into the channel before insertingthe cutting device, and inserting the cutting device through the sheath.

According to another embodiment of the present invention, there isprovided a method of cutting a material comprising a) providing thecutting device of the present invention, b) inserting the cutting deviceinto the material, c) advancing the locking sleeve distally to engagewith the one or more than one notch, thereby locking the blade into thecutting position, d) actuating the cutting device, e) deactuating thecutting device, f) retracting the locking sleeve proximally to disengagefrom the one or more than one notch, thereby unlocking the blade fromthe cutting position, and g) removing the cutting device from thematerial. In one embodiment, inserting the cutting device comprisesadvancing the cutting device through a channel comprising asubstantially straight proximal section having a long axis and a distalsection having a long axis, and the long axis of the distal section iscurved, or where the long axis of the distal section is substantiallystraight but varies at least about 10° off of the long axis of theproximal section. In another embodiment, the method further comprisesadvancing and retracting the cutting device withing the material. Inanother embodiment, the method further comprises inserting a sheath intothe channel before inserting the cutting device, and inserting thecutting device through the sheath.

According to another embodiment of the present invention, there isprovided an enucleation device. The enucleation device comprises aproximal end, a distal end comprising a cutting cap comprising aplurality of deformable blades, and a shaft between the proximal end andthe cutting cap, where the plurality of deformable blades can cutmaterial in a space when the blades not deformed, after accessing thespace through a passage while the blades are deformed, and where thepassage has a smaller cross-sectional area than the lateralcross-sectional area of the undeformed blades while the blades arecutting the material.

In one embodiment, the shaft is flexible. In another embodiment, theenucleation further comprises an axial guidewire lumen between theproximal end and the distal end.

According to another embodiment of the present invention, there isprovided a method of cutting material in a space. The method comprisesa) providing an enucleation according to the present invention, b)accessing the space with the enucleation device, and c) actuating thedevice, thereby effecting cutting of the material. In one embodiment,the method further comprises deforming the blades before actuating thedevice, and accessing the space through a passage while the blades aredeformed, where the passage has a smaller cross-sectional area than thelateral cross-sectional area of the undeformed blades while the bladesare cutting the material. In another embodiment, the passage is curved.In another embodiment, the method further comprises advancing andretracting the cutting device in the space to cut additional material.In another embodiment, accessing the space comprises advancing thecutting device over a guide wire. In another embodiment, the materialcut is selected from the group consisting of intervertebral disk andvertebral body endplate material. In another embodiment, accessing thespace comprises advancing the enucleation device through atranspedicular access passage in a vertebra.

According to another embodiment of the present invention, there isprovided a method of cutting material in a space. The method comprisesa) providing an enucleation device, b) creating a passage to access thespace, c) deforming the blades to fit through the passage, d) advancingthe enucleation device through the passage until the cutting cap passesinto the space, thereby allowing the blades to expand to theirundeformed shape, and e) actuating the enucleation device, therebyeffecting cutting of the material, where the passage has a smallercross-sectional area than the lateral cross-sectional area of theundeformed blades while the blades are cutting the material. In oneembodiment, the method, further comprises advancing and retracting thecutting device in the space to cut additional material. In anotherembodiment, advancing the cutting device through the passage comprisesadvancing the cutting device over a guide wire. In another embodiment,the passage is curved. In another embodiment, the material cut isintervertebral disk. In another embodiment, the material cut isvertebral body endplate material. In another embodiment, the passage isa transpedicular access passage in a vertebra.

According to another embodiment of the present invention, there isprovided a fusion agent containment device for containing a fusion agentcomprising a band or mesh of thin, biocompatible, deformable materialhaving shape memory configured to expand into a substantially circularor oval shape when undeformed. In one embodiment, the fusion agentcontainment further comprises a biocompatible sealant coating the band.

According to another embodiment of the present invention, there isprovided a method of fusing two adjacent vertebrae comprising a)creating a chamber within the intervertebral disk space between twoadjacent vertebrae, b) providing a fusion agent containment deviceaccording to the present invention, c) placed the fusion agentcontainment device within the chamber, thereby allowing the fusion agentcontainment device to expand, d) filling the fusion agent containmentdevice with a fusion agent, and e) allowing the fusion agent to fuse thetwo adjacent vertebrae. In one embodiment, the method further comprisesadditionally fusing the two adjacent vertebrae with a second procedure.

According to another embodiment of the present invention, there isprovided a distraction system for distracting two adjacent vertebraecomprising a) an introducer comprising a proximal insertion portion anda distal anchoring portion comprising a plurality of barbs, and b) aplurality of deformable, spacing components, where each spacingcomponent has a central opening and a plurality of extensions, and eachspacing component configured to stack onto the insertion portion of theintroducer. In one embodiment, the plurality of extensions is selectedfrom the group consisting of three extensions and four extensions.

According to another embodiment of the present invention, there isprovided a distraction system for distracting two adjacent vertebraecomprising a) a proximal connecting portion, b) a distal distractingportion comprising a plurality of strips, each strip is deformable froman extended configuration to a curled configuration, each strip has aproximal end and a distal end, the proximal ends of the strips arejoined to the proximal connecting portion connected at their proximalend to the proximal connecting portion. In one embodiment, the proximalconnecting portion comprises mesh. In another embodiment, each striptapers from the proximal end to the distal end.

According to another embodiment of the present invention, there isprovided a distraction system for distracting two adjacent vertebraecomprising a) a barbed plug having a central axis and comprising acentral portion and a plurality of barbs, b) a ratchet device having acentral axis and comprising a series of transversely separated stripsconnected at one end, where the barbs extend outward from the axialcenter of the barbed plug when undeformed, and contract toward the axialcenter of the barbed plug when deformed, and where the strips uncoilaway from the central axis of the ratchet device when undeformed, andcontract toward the axial center of the ratchet device when deformed.

According to another embodiment of the present invention, there isprovided a method of distracting a superior vertebra from an inferiorvertebra comprising a) providing the distraction system according to thepresent invention, b) creating a chamber between the superior vertebraand the inferior vertebra, c) placing the distraction system in thechamber, thereby distracting the superior vertebra from an inferiorvertebra. In one embodiment, placing the distraction system is performedbilaterally. In another embodiment, placing the distraction systemcomprises placing the distraction system through a channel createdthrough the pedicle of the superior vertebra. In another embodiment,placing the distraction system comprises placing the distraction systemthrough a sheath or hypotube, within a channel created through thepedicle of the superior vertebra.

According to another embodiment of the present invention, there isprovided a method for treating diseases and conditions that change thespacial relationship between a first vertebral body of a first vertebra,a second vertebral body of a second vertebra adjacent the firstvertebra, and a first intervertebral disk between the first vertebralbody and the second vertebral body, or that cause instability of thevertebral column, or both, and a method that allows the surgeon toaccess the first intervertebral disk to restore a more normalthree-dimensional configuration of the first intervertebral disk betweenthe first vertebral body and the second vertebral body, the methodcomprising a) selecting a patient, b) obtaining transpedicular access tothe first intervertebral disk by creating a channel through a pedicle ofthe first vertebra, and c) removing at least part of the firstintervertebral disk through the transpedicular access. In oneembodiment, the patient selected has one or more than one change in thespacial relationship between the first vertebral body of the firstvertebra, the second vertebral body of the second vertebra adjacent thefirst vertebral body, and the first intervertebral disk between thefirst vertebral body and the second vertebral body, and the change inthe spacial relationship causes one or more than one symptom selectedfrom the group consisting of pain, numbness and loss of function, orwhere the change in the spacial relationship causes real or potentialinstability, or a combination of the preceding. In another embodiment,the patient has one or more than one disease or condition selected fromthe group consisting of degeneration of the first intervertebral disk,herniation of the first intervertebral disk, degeneration and herniationof the first intervertebral disk, degenerative scoliosis, an infectionof the first intervertebral disk, an infection of the first vertebralbody, an infection of the second vertebral body, a space occupyinglesions, spinal stenosis, spondylosis, spondylolisthesis, vertebralinstability, a vertebral fracture, and a surgical manipulation of thevertebral column. In another embodiment, obtaining transpedicular accessto the first intervertebral disk is accomplished bilaterally. In anotherembodiment, obtaining transpedicular access to the first intervertebraldisk comprises inserting a bone biopsy needle through one pedicle of thefirst vertebra to create the channel. In another embodiment, obtainingtranspedicular access to the first intervertebral disk comprisesinserting a non-flexible bone drill through one pedicle of the firstvertebra to create or enlarge the channel. In another embodiment, themethod further comprises inserting a sheath into the channel. In anotherembodiment, the method further comprises inserting a retainer tube intothe channel. In another embodiment, the method further comprisesinserting a first flexible drill through the channel and actuating theflexible drill, thereby extending the channel through the firstvertebral body and into the intervertebral disk. In another embodiment,the first flexible drill is a flexible drill according to the presentinvention. In one embodiment, the method further comprises inserting asecond flexible drill through the channel and actuating the flexibledrill, thereby enlarging the channel. In another embodiment, the secondflexible drill is a flexible drill according to the present invention.In another embodiment, the method further comprises inserting aguidewire into the channel for use as a support structure. In anotherembodiment, the method further comprises performing at least part of themethod using an over-the-wire technique. In another embodiment, themethod further comprises removing at least part of the firstintervertebral disk using a cutting device. In one embodiment, thecutting device is a cutting device according to the present invention.In another embodiment, the method further comprises removing at leastpart of the first intervertebral disk using an enucleation device. Inone embodiment, the enucleation device is an enucleation deviceaccording to the present invention. In one embodiment, the methodfurther comprises removing at least part of an endplate of the firstvertebral body or an endplate of the second vertebral body. In oneembodiment, the method further comprises inserting a fusion agentcontainment device into the intervertebral disk, and at least partlyfilling the fusion agent containment device with a fusion agent. In oneembodiment, the fusion agent containment device is a fusion agentcontainment device according to the present invention. In anotherembodiment, the method further comprises inserting a distraction systeminto the intervertebral disk, and allowing the distraction system todistract the first vertebral body from the second vertebral body. In oneembodiment, the distraction system is a distraction system according tothe present invention. In one embodiment, the method further comprisesfusing the first vertebra to the second vertebra through thetranspedicular access. In another embodiment, there is provided a methodof fusing a first vertebra to a second vertebra comprising a) performinga method of the present invention, b) fusing the first vertebra to thesecond vertebra through the transpedicular access, and c) performing asecond fusion procedure to fuse the first vertebra to the secondvertebra. In one embodiment, the method further comprises removing,through the transpedicular access, at least part of a secondintervertebral disk between the second vertebral body and a thirdvertebral body adjacent to the second vertebral body.

FIGURES

These and other features, aspects and advantages of the presentinvention will become better understood from the following description,appended claims, and accompanying figures where:

FIG. 1 is a lateral perspective view of a bone drill according to oneembodiment of the present invention, with the distal drilling end in theinsertion position;

FIG. 2 is a lateral perspective view of the bone drill shown in FIG. 1,with the distal drilling end in the drilling position;

FIG. 3 is an exploded, lateral perspective view of the lowersub-assembly of the bone drill as shown in FIG. 1;

FIG. 4 is an exploded, lateral perspective view of the uppersub-assembly of the bone drill as shown in FIG. 1;

FIG. 5 is a lateral perspective views of several individual componentsof the bone drill as shown in FIG. 1;

FIG. 6 is a lateral perspective view of an optional guiding tip that canbe used with the bone drill as shown in FIG. 1;

FIG. 7 is a lateral perspective view of a cutting device according toone embodiment of the present invention with the distal end in thecutting position;

FIG. 8 is a cutaway, lateral perspective view of the cutting deviceshown in FIG. 7 with the distal end in the insertion position;

FIG. 9 is a close-up, partial, cutaway, lateral perspective view of thedistal end of the cutting device shown in FIG. 7 with the distal end inthe insertion position;

FIG. 10 is a close-up, partial, cutaway, lateral perspective view of thedistal end of the cutting device shown in FIG. 7;

FIG. 11 is a lateral perspective view of an enucleation according to oneembodiment of the present invention with the blades in the insertionposition;

FIG. 12 is a lateral perspective view of the enucleation device shown inFIG. 11, with the blades in the cutting position;

FIG. 13 is an enlarged, lateral perspective view of the distal end ofthe enucleation device shown in FIG. 12;

FIG. 14 is an exploded, lateral perspective view of the enucleationdevice shown in FIG. 12;

FIG. 15 shows both a lateral perspective view (left) and a topperspective view (right) of a fusion agent containment device accordingto one embodiment of the present invention in a deformed configuration;

FIG. 16 shows both a lateral perspective (left) and a top perspectiveview (right) of the fusion agent containment shown in FIG. 15 in anundeformed configuration;

FIG. 17 shows both a lateral perspective (left) and a top perspectiveview (right) of another fusion agent containment device according to oneembodiment of the present invention in a deformed configuration;

FIG. 18 shows both a lateral perspective (left) and a top perspectiveview (right) of the fusion agent containment shown in FIG. 17 in anundeformed configuration;

FIG. 19 shows an isolated section of wire that forms the fusion agentcontainment shown in FIG. 17 and FIG. 18.

FIG. 20 is a lateral perspective view of an introducer of a distractionsystem according to one embodiment of the present invention;

FIG. 21 is a lateral perspective view (left) and a top perspective view(right) of one embodiment of a spacing component of the distractionsystem including the introducer shown in FIG. 20;

FIG. 22 is a lateral perspective view (left) and a top perspective view(right) of one embodiment of another spacing component of thedistraction system including the introducer shown in FIG. 20;

FIG. 23 is a lateral perspective view of another distraction systemaccording to the present invention in the undeformed configuration;

FIG. 24 is a lateral perspective view of the distraction system shown inFIG. 23 in the deformed configuration;

FIG. 25 is a lateral perspective view of the barbed plug of anotherdistraction system according to the present invention in the deformedconfiguration (left) and in the undeformed configuration (right);

FIG. 26 is a top perspective view (left) and a lateral perspective view(right) of the rachet device of the distraction system including thebarbed plug shown in FIG. 25 in the deformed configuration;

FIG. 27 is a top perspective view (left) and a lateral perspective view(right) of the rachet device of the distraction system including thebarbed plug shown in FIG. 25 in the undeformed configuration;

FIG. 28 through FIG. 45 are partial, cutaway, lateral perspective viewsillustrating some aspects of the method of the present invention fortreating diseases and conditions that change the spacial relationshipbetween two vertebral bodies and the intervertebral disk, or that causeinstability of the vertebral column, or both, according to the presentinvention; and

FIG. 46 through FIG. 54 are partial, cutaway, lateral perspective viewsillustrating some aspects of one embodiment of the method of the presentinvention as performed on a first vertebral body of a first vertebra, asecond vertebral body of a second vertebra, an intervertebral diskbetween the first vertebral body and second vertebral body, a thirdvertebral body of a third vertebra and an intervertebral disk betweenthe second vertebral body and third vertebral body.

DESCRIPTION

In one embodiment of the present invention, there is provided a methodfor treating diseases and conditions that change the spacialrelationship between the vertebral bodies and the intervertebral disks,or that cause instability of the vertebral column, or both, that isassociated with less post-operative pain and a lower incidence ofpost-operative morbidity than traditional surgical treatments. Inanother embodiment, there is provided a method for treating diseases andconditions that change the spacial relationship between the vertebralbodies and the intervertebral disks, or that cause instability of thevertebral column, or both, that allows the surgeon to access theintervertebral space to restore a more normal three-dimensionalconfiguration of the space, with or without additionally fusing twoadjacent vertebrae.

In another embodiment of the present invention, there is provided aplurality of devices that can be used with the methods of the presentinvention for treating diseases and conditions that change the spacialrelationship between the vertebral bodies and the intervertebral disks,or that cause instability of the vertebral column, or both, that allowsthe surgeon to access the intervertebral space to restore a more normalthree-dimensional configuration of the space, with or withoutadditionally fusing two adjacent vertebrae, or that can be used forother purposes. The devices and method of the present invention will nowbe disclosed in detail.

As used in this disclosure, the term “intervertebral disk” comprisesboth a normal intact intervertebral disk, as well as a partial,diseased, injured or damaged intervertebral disk, a disk that has beenpartly macerated and empty space surrounded by the remnants of a normalintervertebral disk.

As used in this disclosure, the term “substantially straight passage”means a channel in a material where the channel has a central long axisvarying less than 10° from beginning to end.

As used in this disclosure, the term “curved passage” means a channel ina material where the channel has a central long axis varying more than100 from beginning to end.

As used in this disclosure, the term “comprise” and variations of theterm, such as “comprising” and “comprises,” are not intended to excludeother additives, components, integers or steps.

All dimensions specified in this disclosure are by way of example onlyand are not intended to be limiting. Further, the proportions shown inthese Figures are not necessarily to scale. As will be understood bythose with skill in the art with reference to this disclosure, theactual dimensions of any device or part of a device disclosed in thisdisclosure will be determined by intended use.

In one embodiment, the present invention is a flexible drill comprisinga flexible drilling tip, and capable of orienting the flexible drillingtip at a predetermined position after accessing a material to be drilledthrough a substantially straight passage having a long axis, where thepredetermined position is at least 10° off of the long axis of thesubstantially straight passage. The flexible drill can drill through awide variety of materials, including bone, cartilage and intervertebraldisk, but can also be used to drill through other materials, both livingand nonliving, as will be understood by those with skill in the art withreference to this disclosure. Referring now to FIG. 1, FIG. 2, FIG. 3,FIG. 4, FIG. 5 and FIG. 6, there are shown respectively, a lateralperspective view of the flexible drill with the distal drilling end inthe insertion position; a lateral perspective view of the flexible drillwith the distal drilling end in the flexible drilling position; anexploded, lateral perspective view of the lower sub-assembly of theflexible drill; an exploded, lateral perspective view of the uppersub-assembly of the flexible drill; lateral perspective views of severalindividual components of the flexible drill; and a lateral perspectiveview of an optional guiding tip that can be used with the bone drill.

As can be seen, the flexible drill 100 comprises a lower sub-assembly102 and an upper sub-assembly 104. Referring now to FIG. 1, FIG. 2 and,particularly to FIG. 3 and FIG. 5, the lower sub-assembly 102 comprisesseven components, distally to proximally, as follows: a spin luer lock106, a retainer tube 108, a piston anchor 110, a piston level 112, apiston 114, a distal O-ring 116 and a proximal O-ring 118. The spin luerlock 106 comprises molded nylon or an equivalent material, and is usedto lock the flexible drill 100 to a sheath lining a passage where theflexible drill is to be inserted, and thereby, assists in maintainingstability of the flexible drill 100 during operation. The retainer tube108 comprises stainless steel or an equivalent material, is preferablybetween about 125 mm and 150 mm in axially length, and preferably has aninner diameter of between about 4 and 4.5 mm. The piston anchor 110comprises stainless steel or an equivalent material, and preferably, hasa barb at the distal end (not shown) to snap fit over the spin luer lock106. The piston level 112 comprises machined nylon or an equivalentmaterial, and preferably, has a direction indicator 120 at one end, asshown. The piston 114 comprises machined nylon or an equivalentmaterial, has a distal groove 120 and a proximal grove 124 for matingwith the distal O-ring 116 and the proximal O-ring 118, respectively,and has a slot 126 for mating with a set screw (not shown) passingthrough a hole 128 in the barrel 136. The slot 126 and corresponding setscrew allow precise positioning of the flexible drill 100 in thematerial to be drilled and also limit the extent of retraction of theflexible drilling tip so that the flexible drilling tip enters theretainer tube 108. In another embodiment, the slot 126 is formed as anoval opening in the retainer tube 108 and the key is formed from acorresponding oval block in the guiding tube having a smaller innercircumference. Preferably, the piston 114 has an inner diameter betweenabout 6 mm and about 13 mm. The distal O-ring 116 and the proximalO-ring 118 comprise silicone or an equivalent material, and allow thebarrel 136 and piston 114 to move axially relative to one another.

Referring now to FIG. 1, FIG. 2 and, particularly to FIG. 4 and FIG. 5,the upper sub-assembly 104 comprises thirteen components, distally toproximally, as follows: a flexible drilling tip 130, a guiding tube 132,a barrel knob 134, a barrel 136, a threaded adapter 138, a liner 140, abearing housing 142, a flexible shaft 144, a distal bearing 146, aproximal bearing 148, a collet 150, a bearing cap 152 and a motorreceptacle 154. The flexible drilling tip 130 comprises stainless steelor an equivalent material, is preferably between about 3 mm and 5 mm inmaximum lateral diameter. The flexible drilling tip 130 comprises ahardened burr and a shaft, such as available from Artco, Whittier,Calif. US, or a custom made equivalent burr in stainless steel. Theshaft is cut to an appropriate size by grinding down the proximal end.The dimensions of the flexible drilling tip 130 will vary with theintended use as will be understood by those with skill in the art withreference to this disclosure. By example only, in a preferredembodiment, the burr is between about 2.5 mm and 3 mm in axial length,and the shaft is between about 2.5 mm and 4 mm in length.

The guiding tube 132 has a proximal segment 156 and a distal segment158, and comprises a substance, such as shaped metal alloy, for examplenitinol, that has been processed to return to a shape where the distalsegment 158 has a radius of curvature sufficient to cause the flexibledrilling tip 130 at the end of the distal segment 158 to orient atbetween about 10° and 150° off of the central axis of the proximalsegment when the guiding tube 132 is not subject to distortion.Preferably, the guiding tube 132 has an outer diameter of between about2 mm and 4 mm. The dimensions of the guiding tube 132 are determined bythe intended application of the flexible drill 100. By way of exampleonly, the guide tube has the following dimensions. In a preferredembodiment, the outer diameter of the guiding tube 132 is less thanabout 2.8 mm. In a particularly preferred embodiment, the inner diameterof the guiding tube 132 is greater than about 1.6 mm. In a preferredembodiment, length of the guiding tube 132 is at least about 200 and 250mm. In a preferred embodiment, the straight proximal segment is betweenabout 150 mm and 200 mm. In a preferred embodiment, the distal segment158 is between about 40 mm and 60 mm. In a preferred embodiment, theradius of curvature of the distal segment 158, without distortion, isbetween about 10 mm and 40 mm. In a particularly preferred embodiment,the radius of curvature of the distal segment 158, without distortion,is about 25 mm.

The barrel knob 134 comprises machined nylon or an equivalent material,and has a hole 160 to mate with a dowel pin (not shown). Advancing andretracting the barrel knob 134 with respect to the piston level 112causes the flexible drilling tip 130 to advance and retract in thematerial being drilled. Once drilling is completed, actuation of theflexible drill 100 is stopped, the barrel knob 134 is retracted withrespect to the piston level 112 causing the flexible drilling tip 130 toretract into the retainer tube 108, and the flexible drill 100 isremoved from the substantially straight passage.

The barrel 136 comprises machined nylon or an equivalent material, andpreferably, has an outer diameter of between about 12 mm and 18 mm, andan axial length of between about 75 mm and 125 mm. The threaded adapter138 comprises stainless steel, or an equivalent material, and is used toattach the barrel 136 to the guiding tube 132. The liner 140 comprisespolytetrafluoroethylene (such as TEFLON®) or an equivalent material. Theliner 140 is placed between the flexible shaft 144 and the guiding tube132, and thus, has an outer diameter smaller than the inner diameter ofthe guiding tube 132, and an inner diameter larger than the outerdiameter of the flexible shaft 144. In a preferred embodiment, by way ofexample only, the outer diameter of the liner 140 is between about 0.075mm and 0.125 mm less than the inner diameter of the guiding tube 132.The liner 140 is between about 25 mm and 40 mm shorter than the guidingtube 132.

The bearing housing 142 comprises machined nylon or an equivalentmaterial, is configured to house the distal bearing 146, and has a fineinterior circumferential thread to mate with the threaded adapter 138,thereby allowing an operator to adjust the tension of the flexible shaft144.

The flexible shaft 144 comprises a flexible, solid tubular structure.The flexible shaft 144 comprises stainless steel wire or an equivalentmaterial, and has an outer diameter smaller than the inner diameter ofthe liner 140. By example only, in a preferred embodiment, the flexibleshaft 144 comprises 7 bundles of wire with 19 strands of 0.066 mm wireper bundle. Also by example only, in another preferred embodiment, theflexible shaft 144 comprises four layers of closely braided wire havinga diameter of between about 0.05 mm and 0.06 mm over a single core wireof not more than about 0.25 mm in diameter. The first layer comprises asingle wire, the second layer comprises two wires, the third layercomprises three wires and the fourth layer comprises four wires. Also byexample only, in a preferred embodiment, the cable comprises two layersof wire coaxial and reversibly wound to a single core wire, available aspart number FS 045N042C from PAK Mfg., Inc., Irvington, N.J. US. Theends of the wire are soldered or welded to prevent unraveling. Theflexible shaft 144 has an outer diameter of between about 1 mm and about2.3 mm smaller than the inner diameter of the liner 140. The flexibleshaft 144 has an axial length of about 250 mm to 300 mm.

The distal bearing 146 and the proximal bearing 148 comprise stainlesssteel or an equivalent material. The collet 150 comprises machinedstainless steel or an equivalent material. The bearing cap 152 comprisesmachined nylon or an equivalent material, and is configured to house theproximal bearing 148. The motor receptacle 154 comprises machined nylonor an equivalent material, and has an outer diameter of between about 25mm and 30. The motor receptacle 154 allows a motor to be easily matedwith the flexible drill 100. Preferably, the motor receptacle 154 hasfour windows 162, as shown, to ensure the chuck of the motor (not shown)driving the flexible drill 100 is engaged with the collet 150.

Referring now to FIG. 6, in another embodiment, the upper sub-assembly104 of the flexible drill 100 further comprises a guiding tip 164attached to the guiding tube 132, such as by soldering, just proximal tothe flexible drilling tip 130. The guiding tip 164 comprises a proximaltubular section 166 and a distal flared section 168. The guiding tip164, when present, assists translating the flexible drilling tip 130forward during drilling. The guiding tip 164 comprises a hard,biocompatible material, such as by way of example only, hardenedstainless steel. The dimensions of the guiding tip 164 will vary withthe intended use as will be understood by those with skill in the artwith reference to this disclosure. By example only, in a preferredembodiment, the proximal tubular section 166 is between about 3.5 mm and4 mm in axial length, and the distal flared section 168 is between about2.4 mm and 2.6 mm in axial length. The distal flared section 168 has amaximal sagittal length of between about 2.5 mm and 2.7 mm.

In another embodiment, the flexible drill 100 is configured to be usedin an over-the-wire technique. In this embodiment, the flexible shaft144 comprises a flexible, hollow tubular structure (not shown), that is,has an axial channel for accepting a guide wire, instead of theflexible, solid tubular structure used in the none over-the-wireembodiment. The flexible, hollow tubular structure generally comprisesthe same elements as the flexible, solid tubular structure disclosedabove, except however, for the axial channel. In one embodiment, theflexible, hollow tubular structure has an axial channel having adiameter of between about 0.5 mm and 1.0 mm, and has an outer diameterslightly larger than the outer diameter of the flexible shaft 144 thatis a flexible, solid tubular structure, such as by way of example only,an outer diameter of about 2.0 mm. In one embodiment, the flexible,hollow tubular structure, comprises two layers of 0.3 mm to 0.5 mmdiameter wire that are coiled in opposite directions with the outerlayer wound counterclockwise (available from PAK Mfg., Inc.). When theflexible shaft 144 is configured for over-the-wire use, the outerdiameters of the retainer tube 108, guiding tube 132 and liner 140 areincreased proportionally to the increase in the outer diameter of theflexible shaft 144, and the flexible drilling tip 130 (and guiding tip164, if present) also has a corresponding axial channel to allow passageof the guidewire.

The flexible drill 100 can be assembled in any suitable manner, as willbe understood by those with skill in the art with reference to thisdisclosure. In a preferred embodiment, the flexible drill 100 isassembled as follows. First, the retainer tube 108 is soldered to thepiston anchor 110. Then, the piston level 112 is threaded over thepiston anchor 110 and rotated until the piston level 112 stops. Usingthe direction indicator 120 as reference, the retainer tube 108 is cutto length and the distal end of the retainer tube 108 is cut to form abevel having a cut angle of between about 20° and 45° degrees with thecutting plane and oriented in the same direction as the directionindicator 120. Next, the piston 114 is threaded over the piston anchor110 until the piston 114 stops. Then, the distal O-ring 116 and theproximal O-ring 118 are positioned over the distal groove 120 and theproximal groove 124, respectively, in the piston 114. Next, the guidingtube 132 is soldered to the threaded adapter 138, and the barrel 136 isloosely threaded over the proximal end of the threaded adapter 138.Then, the barrel knob 134 is press fitted over the barrel 136 andsecured by a dowel pin (not shown) inserted into the hole 160 in thebarrel knob 134. Next, the bearing housing 142 is threaded over thethreaded adapter 138 until the bearing housing 142 stops. Then, thedistal segment 158 of the guiding tube 132 is temporarily straightenedand the proximal end of the proximal segment 156 of the guiding tube 132is inserted into the piston 114 and retainer tube 108. Next, the distalend of the barrel 136 is slid over the proximal end of the piston 114.Then, the hole 160 in the barrel knob 134 for the set screw is alignedwith the slot 126 in the piston 114, and a set screw (not shown) isscrewed into the hole and slot 126. Next, the distal segment 158 of theguiding tube 132 is aligned with the cutting plane of the retainer tube108 by rotating the threaded adapter 138, and the threaded adapter 138is secured to the barrel 136. Then, the flexible drilling tip 130 issoldered to the flexible shaft 144. Next, the liner 140 is slid over theflexible shaft 144. Then, the barrel knob 134 and piston level 112 aredistracted from each other, thereby straightening the distal segment 158of the guiding tube 132 inside the retainer tube 108, and the liner 140with the flexible shaft 144 is slid into the distal end of the guidingtube 132. Next, the distal bearing 146 is placed into the bearinghousing 142 through the flexible shaft 144. Then, the collet 150 is slidover the flexible shaft 144 and attached to the flexible shaft 144, suchas by crimping or soldering. Next, the proximal bearing 148 is slid overthe collet 150, and the bearing cap 152 is placed over the bearing andsecured to the bearing housing 142. Then, the motor receptacle 154 ispress fitted to the barrel 136 until the motor receptacle 154 stops.Finally, the spin luer lock 106 is snap fit onto the piston anchor 110.In one embodiment, a thin-walled hypodermic tube, not shown, is slid andcrimped over the proximal portion of the flexible shaft 144 to increasethe transmission of torque from the motor.

In one embodiment, the present invention is a method of using a flexibledrill comprising a flexible drilling tip, and having the ability toorient the flexible drilling tip at a predetermined position afteraccessing a material to be drilled through a substantially straightpassage, where the predetermined position is at least 10° off of thelong axis of the substantially straight passage, or is between about 10°and 150° off of the long axis of the substantially straight passage. Ina preferred embodiment, the predetermined position is at least about 90°off of the long axis of the substantially straight passage. In anotherpreferred embodiment, the predetermined position is between about 90°and 120° off of the long axis of the substantially straight passage.

In one embodiment, the method comprises drilling a substantiallystraight passage through a first material. Then, a flexible drill isprovided where the flexible drill comprises a flexible drilling tip,where the flexible drill has the ability to orient the flexible drillingtip at a predetermined position after accessing a material to be drilledthrough a substantially straight passage, and where the predeterminedposition is at least 10° off of the long axis of the substantiallystraight passage. Next, the flexible drill is inserted into thesubstantially straight passage and advanced through the substantiallystraight passage and the flexible drilling tip is advanced until theflexible drilling tip exits the substantially straight passage into asecond material, thereby allowing the flexible drilling tip to orient tothe predetermined position within the second material. Then, theflexible drill is actuated, thereby drilling into the second material.Next, actuation of the flexible drill is stopped, thereby stopping theflexible drilling into the second material. Then, the flexible drill isremoved through the substantially straight passage.

In a preferred embodiment, the flexible drill provided is a flexibledrill according to the present invention. In another preferredembodiment, the space is an intervertebral disk space between a firstvertebra and a second vertebra. In another preferred embodiment, thefirst material is pedicle bone of either the first vertebra or thesecond vertebra. In another preferred embodiment, the first material ispedicle bone of either the first vertebra or the second vertebra, andthe second material is intervertebral disk between the first vertebraand the second vertebra.

In another embodiment, the present invention is a method for removingintervertebral disk between a first vertebra and a second vertebra. Themethod comprises drilling a substantially straight passage through apedicle of either the first vertebra or the second vertebra. Then, aflexible drill is provided where the flexible drill comprises a flexibledrilling tip, where the flexible drill has the ability to orient theflexible drilling tip at a predetermined position within theintervertebral disk space after accessing the intervertebral disk spacethrough a substantially straight passage through a pedicle, and wherethe predetermined position is at least 10° off of the long axis of thesubstantially straight passage. Next, the flexible drill is insertedinto the substantially straight passage in the pedicle and advancedthrough the substantially straight passage. Then, the flexible drillingtip is advanced until the flexible drilling tip exits the substantiallystraight passage into the intervertebral disk, thereby allowing theflexible drilling tip to orient to the predetermined position within theintervertebral disk. Next, the flexible drill is actuated, therebydrilling into the intervertebral disk. Then, actuation of the flexibledrill is stopped, thereby stopping the flexible drilling into theintervertebral disk. Next, the flexible drill is removed through thesubstantially straight passage.

In a preferred embodiment, the flexible drill provided is a flexibledrill according to the present invention. In another preferredembodiment, the method further comprises inserting a sheath, such as forexample only, a stainless steel sheath, with an inner diameter less thanabout 5 mm and tapered at the distal end into the substantially straightpassage before inserting the flexible drill, then inserting the flexibledrill through the sheath. In a preferred embodiment, the sheath is aluer lock at the proximal end to mate with drill after inserting theflexible drill. In a preferred embodiment, the flexible drill has adirection indicator and the flexible drilling tip is oriented within theintervertebral disk using the direction indicator.

In one embodiment, the method comprises using an over-the-wiretechnique. In this embodiment, a guide wire is place in the flexibleshaft and drilling tip and, upon removal of the flexible drill from thesubstantially straight passage, the guide wire is left in place to allowpassage of the next device into the substantially straight passage andinto the space that has been drilled.

In another embodiment, the present invention is a cutting devicecomprising a pivoting blade connected to the distal end of a flexibleshaft, where the cutting device can be inserted into a material to becut after accessing the material through a channel having asubstantially straight proximal section having a long axis and a distalsection having a long axis, where the long axis of the distal section iscurved, or where the long axis of the distal section varies at leastabout 10° off of the long axis of the proximal section. The cuttingdevice can cut through a wide variety of materials, including bone,cartilage and intervertebral disk, but can also be used to drill throughother materials, both living and nonliving, as will be understood bythose with skill in the art with reference to this disclosure. Referringnow to FIG. 7, FIG. 8, FIG. 9 and FIG. 10, there are shown,respectively, a lateral perspective view of the cutting device with thedistal end in the cutting position; a cutaway, lateral perspective viewof the cutting device with the distal end in the insertion position; aclose-up, partial, cutaway, lateral perspective view of the distal endof the cutting device with the distal end in the insertion position; anda close-up, partial, cutaway, lateral perspective view of the distal endof the cutting device with the distal end in the cutting position.

As can be seen in FIG. 7 and FIG. 8, the cutting device 200 comprises aproximal end 202 and a distal end 204. The proximal end 202 comprises amotor adapter 206 connected distally to a bearing housing 208, such asfor example only, by press fitting. The motor adapter 206 is used toconnect the cutting device 200 to a motor drive 210, partially shown inFIG. 7 and FIG. 8, capable of transmitting axial rotation to the distalend 204 of the cutting device 200 to function as disclosed in thisdisclosure. Both the motor adapter 206 and the bearing housing 208 cancomprise any suitable material capable of being machined or molded intothe proper shape, and having suitable properties, as will be understoodby those with skill in the art with reference to this disclosure. In apreferred embodiment, both of the motor adapter 206 and the bearinghousing 208 comprise a polymer. In a particularly preferred embodiment,both the motor adapter 206 and the bearing housing 208 comprise DELRIN®(E. I. du Pont De Nemours and Company Corporation, Wilmington, Del. US).The motor drive 210 used with the cutting device 200 of the presentinvention can be any suitable motor drive 210. In a preferredembodiment, the motor drive 210 is a variable speed motor drive. In oneembodiment, by way of example only, the motor drive 210 is an NSKElecter EMAX motor drive (NSK Nakanishi Inc., Tochigi-ken, Japan).

Referring now to FIG. 8, the cutting device 200 further comprises anadapter tube 212, having a proximal end configured to mate with thehousing of the motor drive 210 and having a distal end fitted and fixed,such as by soldering, into the proximal end of a drive shaft 214. Theadapter tube 212 transmits torque from motor drive 210 to the distal end204 of the cutting device 200. The adapter tube 212 can comprise anysuitable material for the purpose disclosed in this disclosure. In oneembodiment, the adapter tube 212 comprises stainless steel. In anotherembodiment, the adapter tube 212 has an inner diameter of about 1.9 mmand 2 mm, and an outer diameter of about 2.4 mm. In another embodiment,the adapter tube 212 is about 25 mm in axial length. In one embodiment,by way of example only, the adapter tube 212 is part number 13tw, fromMicro Group Inc., Medway, Mass. US, ground to appropriate dimensions.

Referring now to FIG. 7 and FIG. 8, the cutting device 200 furthercomprises a drive tube 216 having a proximal end fitted and fixed, suchas by silver soldering, into the distal end of the adapter tube 212 andextending distally toward the distal end 204 of the cutting device 200.The drive tube 216 provides rigidity to the cutting device 200 allowingadvancement and retraction of the cutting device 200 and transmitstorque from motor drive 210 to the distal end 204 of the cutting device200. In one embodiment, the drive tube 216 comprises stainless steel. Inanother embodiment, the drive tube 216 has an axial length of about 200mm. In another embodiment, the drive tube 216 has an inner diameter ofabout 1.3 mm and an outer diameter of about 1.8 mm. In a preferredembodiment, by way of example only, the drive tube 216 is part number15H, Micro Group Inc.

Referring now to FIG. 8, the cutting device 200 further comprises twobearings 218 pressed into the bearing housing 208, and comprises a driveshaft 214 within the bearing housing 208 and supported between thebearings 218. The bearings 218 and drive shaft 214 assist in translatingtorque from motor drive 210 to the distal end 204 of the cutting device200 to create smooth axial rotation of the distal end 204 of the cuttingdevice 200. The bearings 218 can comprise any suitable bearings, as willbe understood by those with skill in the art with reference to thisdisclosure. In one embodiment, the bearings 218 are miniature, highspeed stainless steel radial bearings, such as part number 57155k53,McMaster-Carr Supply Co., Sante Fe Springs, Calif. US). The drive shaft214 is an interface between the bearings 218 and the drive tube 216 andprovides smooth rotation for the distal end 204 of the cutting device200. In a preferred embodiment, the drive shaft 214 has a 6-32 femalethread that is about 16 mm deep on distal end 204, and has a retainingring groove and a 1.9 mm diameter hole drilled through the long axis onthe proximal end. The drive shaft 214 is counter bored between about 2.3mm and 2.4 mm in diameter and about 5 mm deep on the proximal end. Thedrive shaft 214 can be any suitable material, as will be understood bythose with skill in the art with reference to this disclosure. In oneembodiment, the drive shaft 214 is machined stainless steel.

Referring now to FIG. 7 and FIG. 8, the cutting device 200 furthercomprises a collar 220 press fitted onto the distal end of the driveshaft 214 until the collar 220 is flush with the distal end of the driveshaft 214. An operator can prevent rotation of the drive shaft 214during advancement and actuation of the distal end of the cutting device200 by grasping the collar 220 to prevent rotation of the collar 220,and hence, the drive shaft 214. The collar 220 can comprise any suitablematerial capable of being machined or molded into the proper shape, andhaving suitable properties, as will be understood by those with skill inthe art with reference to this disclosure. In one embodiment, the collar220 comprises a polymer, such as for example only, DELRIN®.

Referring now to FIG. 7, FIG. 8 and particularly FIG. 10, the cuttingdevice 200 further comprises a flexible shaft 222 having a proximal endextending through the drive tube 216, and fitted and fixed, such as bysoldering, flush into the distal end of the adapter tube 212.Additionally, the distal end of the drive tube 216 is fixed to theflexible shaft 222, such as by crimping or silver soldering. In oneembodiment, the flexible shaft 222 comprises constructing from amulti-filar winding with a solid core. In another embodiment, theflexible shaft 222 has an axial length of about 300 mm. In anotherembodiment, the flexible shaft 222 has a diameter of about 1.25 mm. In apreferred embodiment, by way of example only, the flexible shaft 222 ispart number FS045N042C, PAK Mfg., Inc., Irvington, N.J. US.

The drive shaft 214, adapter tube 212, drive tube 216 and flexible shaft222 assembly are inserted into the bearing housing 208, held in placeusing a retaining ring 224, and transmit torque from motor drive 210 tothe distal end of the cutting device 200. In a preferred embodiment, byway of example only, the retaining ring 224 is part number 98410A110,McMaster-Carr Industrial Supply.

Referring now to FIG. 7, FIG. 8, FIG. 9 and FIG. 10, the cutting device200 further comprises a braided tube 226 surrounding the flexible shaft222 throughout the length of the flexible shaft 222. The braided tube226 increases column stiffness. In one embodiment, the braided tube 226comprises stainless steel. In another embodiment, the braided tube 226has an axial length of about 220 mm. In a preferred embodiment, by wayof example only, the braided tube 226 can be fabricated by Viamed Corp.,South Easton, Mass. US.

The proximal end of the braided tube 226 is soldered to the head of a6-32 cap screw 228 forming a hollow joint. In one embodiment, the capscrew 228 is a 6-32×1.9 mm long socket head cap screw, such as partnumber 92196A151, McMaster-Carr Industrial Supply, that has beenmodified by drilling a 1.85 mm diameter hole through the long axis toprovide a through lumen for the drive tube 216. The cap screw 228 cancomprise any suitable material capable of being machined or molded intothe proper shape, and having suitable properties, as will be understoodby those with skill in the art with reference to this disclosure. In oneembodiment, the cap screw 228 comprises stainless steel.

The cutting device 200 further comprises a thumb screw knob 230 pressedfitted flush onto the head of the cap screw 228. The thumb screw knob230 can comprise any suitable material capable of being machined ormolded into the proper shape, and having suitable properties, as will beunderstood by those with skill in the art with reference to thisdisclosure. In a preferred embodiment, the thumb screw knob 230comprises a polymer, such as for example only, DELRIN®.

The cutting device 200 further comprises a lock nut 232 fully screwedonto the cap screw 228. The lock nut 232 and braided tube 226 are placedover the distal end of the flexible shaft 222 and drive tube 216, andthe cap screw 228 is fully screwed into the drive shaft 214. The capscrew 228, thumb screw knob 230 and lock nut 232 assembly allows theoperator to advance distally or retract proximally the braided tube 226,and to lock the braided tube 226 into a desired position.

Referring now to FIG. 10, the cutting device 200 further comprises ashrink tube 234 covering all of the distal end of the flexible shaft 222and between the inner surface of the braided tube 226 and the outersurface of the flexible shaft 222. In one embodiment, the shrink tube234 comprises Polytetrafluoroethylene (available from Zeus IndustrialProducts, Orangeburg, S.C. US). In another embodiment, the shrink tube234 has an inner diameter of about 1.3 mm and an outer diameter of about1.5 mm. In another embodiment, the shrink tube 234 is about 160 mm long.

Referring now to FIG. 9 and FIG. 10, the distal end of the cuttingdevice 200 further comprises a hinge 236 attached to the distal end ofthe flexible shaft 222, such as for example by silver soldering. Thehinge 236 can comprise any suitable material capable of being machinedor molded into the proper shape, and having suitable properties, as willbe understood by those with skill in the art with reference to thisdisclosure. In one embodiment, the hinge 236 comprises stainless steel.The cutting device 200 further comprises a blade 238 attached to thedistal end of the hinge 236 in a manner that allows the blade 238 topivot to at least about 90° with respect to the long axis of the cuttingdevice 200, such as by a dowel 240, as shown, from a first, insertionposition, FIG. 9, to a second, cutting position, FIG. 10. The blade 238has a circumferential cutting edge and one or more than one notch 242,such as the two notches shown in FIG. 9 and FIG. 10. In a preferredembodiment, as shown, the blade 238 has a rounded distal tip suitablefor macerating spinal nucleus and abrading vertebral body endplates.However, other blade shapes could also be used depending on the intendeduse of the cutting device 200, as will be understood by those with skillin the art with reference to this disclosure. The blade 238 can compriseany suitable material capable of being machined or molded into theproper shape, and having suitable properties, as will be understood bythose with skill in the art with reference to this disclosure. In oneembodiment, the blade 238 comprises stainless steel.

In a preferred embodiment, the cutting device 200 further comprises alocking sleeve 244 attached to the distal end of the braided tube 226,such as by silver soldering. The locking sleeve 244 can be advanceddistally and retracted proximally by manipulating the braided tube 226using the cap screw 228, thumb screw knob 230 and lock nut 232 assembly.As shown in FIG. 9 and FIG. 10, when the locking sleeve 244 is retractedproximally, the distal end of the locking sleeve 244 disengages from theone or more than one notch 242 in the blade 238 and allows the blade 238to pivot freely. When the locking sleeve 244 is advanced distally, thedistal end of the locking sleeve 244 is configured to mate withcorresponding one or more than one notch 242 in the blade 238, and serveto lock the blade 238 at 90° with respect to the long axis of thecutting device 200. The locking sleeve 244 can comprise any suitablematerial capable of being machined or molded into the proper shape, andhaving suitable properties, as will be understood by those with skill inthe art with reference to this disclosure. In one embodiment, thelocking sleeve 244 comprises stainless steel. In another embodiment, thelocking sleeve 244 has an inner diameter of about 2.5 mm and an outerdiameter of about 2.6 mm. In another embodiment, the locking sleeve 244has a length of about 3.8 mm.

Referring now to FIG. 7, FIG. 8, FIG. 9 and FIG. 10, In a preferredembodiment, the distal end 204 of the cutting device 200 furthercomprises a sheath 246 movably surrounding the braided tube 226 distallyand connected to a luer hub 248 proximally. The distal end of the sheath246 has a bevel 250, as shown in the Figures. In one embodiment, thebevel makes an angle of about 30° with the long axis of the cuttingdevice 200. In a preferred embodiment, the distal end of the cuttingdevice 200 is advanced into and retracted from the space where drillingis required through the sheath 246. During retraction, the beveleddistal end of the sheath 246 contacts the blade 238, causing the blade238 to disengage from the locking sleeve 244 and pivot to the insertionposition. The sheath 246 and luer hub 248 can comprise any suitablematerial capable of being machined or molded into the proper shape, andhaving suitable properties, as will be understood by those with skill inthe art with reference to this disclosure. In one embodiment, the sheath246 comprises a polymer such as PEBAX® (Atochem Corporation, Puteaux,FR). In another embodiment, the luer hub 248 comprises polycarbonate. Inone embodiment, the sheath 246 has an inner diameter of about 2.8 mm andan outer diameter of about 3.6 mm. In another embodiment, the sheath 246is about 150 mm long.

The cutting device 200 of the present invention can be used to create acavity in any suitable material, including living tissue, such as bone,connective tissue or cartilage. Further, the cutting device 200 can beused to debulk a tumor. Additionally, the cutting device 200 can be usedto increase the cross-sectional area of a channel by moving the cuttingdevice 200 within the channel while the motor is actuated.

The cutting device 200 is used as follows. A channel is made in livingbone or other suitable material having a circumference large enough toaccommodate the distal end of the cutting device 200. Next, the sheath246 is inserted into the channel. Then, the cutting device 200 isinserted into the sheath 246 and advanced until the distal end of thecutting device 200, including the blade 238, exits the sheath 246distally. The preset radius of the distal end of the blade 238 causesthe blade 238 to pivot when it comes into contact with any surface.Next, the braided tube 226 with attached locking sleeve 244 are advanceddistally causing the locking sleeve 244 to engage the one or more thanone notch 242 in the blade 238. The motor drive 210 is actuated causingthe drive cable to rotate axially and, thereby rotating the cuttingblade 238. Cutting can be performed by maintaining the cutting device200 in a stationary position, or can be performed while moving thecutting device 200 proximally and distally increasing the volume ofmaterial that is cut. Once cutting is complete, the motor is deactuated,causing the drive cable to cease rotating axially, thereby stopping thecutting motion of the blade 238. The sheath 246 is advanced distally,causing the locking sleeve 244 to disengage from the blade 238 and theblade 238 to return to its insertion position. In one embodiment, thecutting device 200 is then withdrawn through the sheath 246. In anotherembodiment, the sheath 246 is then advanced to a second position and thesteps repeated, thereby cutting at a second location. In a preferredembodiment, the debris from the cutting is removed using suction, byflushing with a suitable solution such as saline, or by a combination ofsuction and flushing, using techniques known to those with skill in theart.

In another embodiment, the present invention is an enucleation devicecomprising a plurality of deformable blades that can cut material in aspace when the blades are not deformed, after accessing the spacethrough a channel while the blades are deformed, where the channel has asmaller cross-sectional area than the cross-sectional area of theplurality of undeformed blades. Referring now to FIG. 11, FIG. 12, FIG.13 and FIG. 14, there are shown, respectively, a lateral perspectiveview of the enucleation device with the blades in the insertionposition; a lateral perspective view of the enucleation device with theblades in the cutting position; an enlarged, lateral perspective view ofthe distal end of the enucleation device; and an exploded, lateralperspective view of the enucleation device. As can be seen in theFigures, the enucleation device 300 comprises a proximal end 302 and adistal end 304. In one embodiment, the enucleation device 300 furthercomprises the following parts: a motor adapter 306, a chuck adapter 308,a bearing cap 310, a proximal bearing 312, a collet adapter 314, adistal bearing 316, a bearing housing 318, a threaded adapter 320, abarrel 322, a barrel knob 324, a spacer tube 326, a hypotube 328, ashaft 330, a shrink tube 332, and a cutting cap 334 comprising aplurality of blades 336. However, some of the parts, such as the chuckadapter 308 are optional, and other parts can be substituted forequivalent parts, as will be understood by those with skill in the artwith reference to this disclosure. The parts of the enucleation device300 can comprise any suitable material capable of being machined ormolded into the proper shape, and having suitable properties, as will beunderstood by those with skill in the art with reference to thisdisclosure. In a preferred embodiment, the motor adapter 306, bearingcap 310, bearing housing 318, barrel 322, barrel knob 324 and spacertube 326 comprise a polymer or an equivalent material. In a particularlypreferred embodiment, they comprise DELRIN®. In another preferredembodiment, the chuck adapter 308, proximal bearing 312, collet adapter314, distal bearing 316, threaded adapter 320, hypotube 328, and hollowshaft comprise stainless steel or an equivalent material. In anotherpreferred embodiment, the shrink tube 332 comprisespolytetrafluoroethylene (such as TEFLON®) or an equivalent material. Inanother preferred embodiment, the cutting cap 334 with its plurality ofblades 336 comprises a shaped metal alloy, such a nitinol, that has beenprocessed to return to an orthogonally-expanded cutting configurationsuitable for cutting when undeformed. These parts will now be disclosedin greater detail.

Referring again to FIG. 11, FIG. 12, FIG. 13 and FIG. 14, Theenucleation device 300 comprises a motor adapter 306 at the proximal end302 connected distally to the barrel 322. The motor adapter 306 is usedto connect the enucleation device 300 to a motor drive (not shown),capable of transmitting axial rotation to the distal end 304 of theenucleation device 300 to function as disclosed in this disclosure. Inone embodiment, when used for cutting intervertebral disk material inthe method of the present invention, the dimensions of the motor adapter306 are about 11 cm in axial length by 3.8 cm in maximum outer diameterby 3.3 cm in maximum inner diameter. However, the dimensions can be anysuitable dimensions for the intended use, as will be understood by thosewith skill in the art with reference to this disclosure. The motor driveused with the enucleation device 300 of the present invention can be anysuitable motor drive. In a preferred embodiment, the motor drive is avariable speed motor drive. In one embodiment, by way of example only,the motor drive is an NSK Electer EMAX motor drive (NSK Nakanishi Inc.).In another embodiment, the motor drive is a hand drill (for example, P/NC00108, Vertelink Corporation, Irvine, Calif. US) connected to the motoradapter 306 by interfacing with the optional chuck adapter 308.

The enucleation device 300 further comprises a bearing assembly,comprising the bearing cap 310, the proximal bearing 312, the colletadapter 314, the distal bearing 316, and the bearing housing 318. Thebearing housing 318 retains the proximal bearing 312, the collet adapter314 and the distal bearing 316, which are preferably pressed into thebearing housing 318. In a preferred embodiment, the proximal bearing 312and the distal bearing 316 are high-speed stainless steel radialbearings, such as for example only, P/N 57155k53, McMaster-Carr SupplyCompany, Santa Fe Springs, Calif. US. The collet adapter 314 is used toadapt the shaft 330 to a motor collet of the motor drive (not shown).The collet adapter 314 is connected to the shaft 330, such as forexample only, by silver soldering. In one embodiment, the collet adapter314 has an axial lumen for receiving a guidewire. In a preferredembodiment, the axial lumen has a diameter of about 2 mm.

The enucleation device 300 further comprises a barrel 322, whichpreferably has an axial lumen for receiving a guidewire, and a barrelknob 324 overlying the barrel 322, such as for example, by being pressfitted on the barrel 322. The barrel knob 324 allows an operator tograsp the enucleation device 300 while advancing and retracting theenucleation device 300.

The enucleation device further comprises a hypotube 328. In oneembodiment, when used for cutting intervertebral disk material in themethod of the present invention, the hypotube 328 has an outer diameterof about 3.8 mm, an inner diameter of about 3 mm and an axial length ofabout 175 mm.

The enucleation device further comprises a shaft 330. In one embodiment,the shaft 330 has an axial lumen for receiving a guidewire. In apreferred embodiment, the shaft 330 is flexible to permit theenucleation device 300 to be advanced through a curved passage. In oneembodiment, the shaft 330 is part number FS085T11C, PAK Mfg., Inc. Inone embodiment, when used for cutting intervertebral disk material inthe method of the present invention, the shaft 330 has an outer diameterof about 2 mm, an inner diameter of about 3 mm and an axial length ofabout 350 mm. When used with a guidewire, the shaft 330 has an innerdiameter of about 1 mm.

The enucleation device 300 further comprises a threaded adapter 320 thatconnects the bearing assembly and the hypotube 328 to the barrel 322. Inone embodiment, the threaded adapter 320 has a single thread proximallyfor interfacing with the bearing housing 318. In one embodiment, thethreaded adapter 320 has an axial lumen for receiving a guidewire. In apreferred embodiment, the axial lumen has a diameter of between about 3mm and 4 mm. In a preferred embodiment, the threaded adapter 320 has anaxial length of about 13 mm and a maximum outer diameter of about 5 mm.

The enucleation device 300 further comprises a spacer tube 326 having anaxial lumen. The spacer tube 326 decreases the diameter of the axiallumen of the barrel 322. In one embodiment, the axial lumen of thespacer tube 326 has a diameter of about 4 mm.

The enucleation device 300 further comprises a shrink tube 332 coveringthe distal end of the shaft 330. The shrink tube 332 provides a bearingsurface between the hypotube 328 and shaft 330. In one embodiment, whenused for cutting intervertebral disk material in the method of thepresent invention, the shrink tube 332 has an outer diameter of about3.3 mm, an inner diameter of about 2.5 mm and an axial length of about350 mm. By way of example only, a suitable shrink tube can be purchasedfrom Zeus Industrial Products, Orangeburg, S.C. US.

The enucleation device 300 further comprises a cutting cap 334 at thedistal end 304 of the enucleation device 300. The cutting cap 334comprises a plurality of deformable blades 336 that orthogonally-expandwhen the blades 336 are not deformed. Each blade 336 has one or morethan one cutting edge. In one embodiment, the plurality of bladescomprises two or more than two blades. In another embodiment, theplurality of blades comprises three blades. In a preferred embodiment,the plurality of blades comprises four blades. The blades 336, andpreferably, the entire cutting cap 334, comprises a shaped metal alloy,such a nitinol, that has been processed to return the blades 336 to anorthogonally-expanded cutting configuration suitable for cutting whenundeformed. In one embodiment, when used for cutting intervertebral diskmaterial in the method of the present invention, the cutting cap 334 hasan outer diameter of about 3 mm, an inner diameter of about 2.2 mm andan axial length of about 11 mm when deformed. When undeformed andactivated, the spinning blades cover a cross-sectional area of about 1.8cm, that is, an area having a diameter of about 1.5 cm.

The enucleation device 300 can be made by any suitable method, as willbe understood by those with skill in the art with reference to thisdisclosure. In one embodiment, the enucleation device 300 is made inpart by the following steps. The spacer tube 326 is introduced over thedistal end of the hypotube 328 and barrel 322 and is pressed into thebarrel until the spacer tuber 326 is flush with the distal end of thebarrel 322. The threaded adapter 320 is connected to the proximal end ofhypotube 328, such as for example only, by silver soldering, and thethreaded adapter 320 and hypotube 328 are inserted into the proximal endof the barrel 322 until they come to a stop and they are secured to thebarrel 322 with a setscrew (not shown). The bearing housing 318 isscrewed onto the threaded adapter 320 and a distal bearing 316 ispressed into the bearing housing 318. The shaft 330 is inserted into thebearing housing 318 through the distal bearing 316 and bearing housing318, and the collet adapter 314 is placed over the shaft 330 andsoldered onto the shaft approximately 50 mm from the proximal end of theshaft 330. The proximal bearing 312 is placed over the proximal end ofthe collet adapter 314. The bearing cap 310 is screwed onto the proximalend of the bearing housing 318 until the bearing cap 310 stops. Thebarrel assembly is inserted into the motor adapter 306 and is keyedthrough a slot in the side of the motor adapter 306. The shrink tube 332is placed over the distal end of the shaft 330. The cutting cap 334 iscrimped or bonded to the distal end of the shaft 330.

The enucleation device of the present invention can be used to cut anysuitable material, as will be understood by those with skill in the artwith reference to this disclosure. In a preferred embodiment, theenucleation device is used to cut away intervertebral disk from anintervertebral space between two vertebral bodies after accessing theintervertebral space through a passage in the pedicle of the vertebrasuperior to the intervertebral space, where the passage has a smallercross-sectional area than the lateral cross-sectional area of theundeformed blades while the blades are cutting the material. In apreferred embodiment, the enucleation device is also used to cut awayvertebral body endplates bordering the intervertebral space.

By way of example only, the enucleation device can be used to cutmaterial in a space when the blades are not deformed, after accessingthe space through a channel while the blades are deformed, where thechannel has a smaller cross-sectional area than the cross-sectional areaof the plurality of undeformed blades while the blades are cutting thematerial as follows. First, the blades are deformed to fit through apreviously created channel. Deformation comprises moving the distal tipsof each blade toward the long axis of the enucleation device,preferably, until the long axis of each blade is coaxial with the longaxis of the enucleation device. Next, the cutting cap of the enucleationdevice is advanced through the channel, and the distal end of theenucleation device is allowed to pass into the space, thereby allowingthe blades to expand orthogonally, that is to allow the distal tips ofeach blade to move away from the long axis of the enucleation device,perpendicular to the long axis of the enucleation device, to theirundeformed shape. In a preferred embodiment, the channel issignificantly curved, and the enucleation device has a shaft allowingthe enucleation device to follow the curvature of the channel as theenucleation device is advanced. Next, the enucleation device is actuatedcausing the blades to rotate, thereby affecting cutting of the material.In a preferred embodiment, the blades are rotated at between about 100and 15000 RPM. Additionally, the enucleation device can be advanced andretracted in the space to cut additional material. Once completed, theenucleation device is withdrawn causing the blades to deform until theyhave been withdrawn from the channel.

In a preferred embodiment, the enucleation device is advanced throughthe channel over a guide wire. In another preferred embodiment, theenucleation device is passed through a sheath lining the channel. Inanother preferred embodiment, the material cut is intervertebral disk.In a particularly preferred embodiment, the shaft of the enucleationdevice is flexible to permit the enucleation device to advance through acurved passage. In another particularly preferred embodiment, thematerial is vertebral body endplate material. In another particularlypreferred embodiment, the channel is a transpedicular access channel ina vertebra.

In another embodiment, the present invention is a fusion agentcontainment device for containing a fusion agent within a chamber formedwithin an intervertebral disk space. Referring now to FIG. 15 and FIG.16, there are shown in each Figure a lateral perspective view (left) anda top perspective view (right) of a fusion agent containment device 400according to one embodiment of the present invention expanding from afirst, deformed configuration, FIG. 15 to a second undeformedconfiguration, FIG. 16. As can be seen, the fusion agent containmentdevice 400 comprises a band comprising a thin, biocompatible, deformablematerial having shape memory configured to expand into a substantiallycircular or oval shape when undeformed. In a preferred embodiment, theband comprises a shaped metal alloy, such as nitinol, that has beenprocessed to return to an undeformed configuration, approximating theboundaries of the empty space within the intervertebral disk spacecreated during the method of the present invention. In a particularlypreferred embodiment, the band is coated with a biocompatible sealant,such as hydrogel. The dimensions of the fusion agent containment device400 will vary with the intended use as will be understood by those withskill in the art with reference to this disclosure. By example only, ina preferred embodiment, the band expands upon deployment toapproximately 1 cm in height and 2 cm in diameter.

In another embodiment, the present invention is a fusion agentcontainment device for containing a fusion agent within a chamber formedwithin an intervertebral disk space. Referring now to FIG. 17 and FIG.18, there are shown in each Figure a lateral perspective view (left) anda top perspective view (right) of a fusion agent containment device 500according to one embodiment of the present invention expanding from afirst, deformed configuration, FIG. 17 to a second undeformedconfiguration, FIG. 18. As can be seen, the fusion agent containmentdevice 500 comprises wire comprising a thin, biocompatible, deformablematerial having shape memory configured to expand into a substantiallycircular or oval shape when undeformed. The fusion agent containmentdevice 500 can be formed from wire shaped into a variety configurations,as will be understood by those with skill in the art with reference tothis disclosure. FIG. 19 shows an isolated section of wire 502 thatforms the fusion agent containment shown in FIG. 17 and FIG. 18. In apreferred embodiment, the wire comprises a mesh, as shown in FIG. 38,FIG. 53 and FIG. 54, because a mesh can be deformed bothcircumferentially and axially. In one embodiment, the wire comprises ashaped metal alloy, such as nitinol, that has been processed to returnto an undeformed configuration, approximating the boundaries of theempty space within the intervertebral disk space created during themethod of the present invention. In a particularly preferred embodiment,the wire mesh is coated with a biocompatible sealant, such as hydrogel.The dimensions of the fusion agent containment device 500 will vary withthe intended use as will be understood by those with skill in the artwith reference to this disclosure. By example only, in a preferredembodiment, the band expands upon deployment to approximately 1 cm inheight and 2 cm in diameter.

In another embodiment, the present invention is a method of fusing twoadjacent vertebrae using a fusion agent containment device of thepresent invention. The method comprises, first, creating a chamberwithin the intervertebral disk space between two adjacent vertebrae.Next, a fusion agent containment device according to the presentinvention is provided and is placed within the chamber and allowed toexpand to its undeformed configuration. Then, the fusion agentcontainment device is filled with a fusion agent and the fusion agent isallowed to fuse the two adjacent vertebrae. In a preferred embodiment,the method further comprises additionally fusing the two adjacentvertebrae with a second procedure.

In another embodiment, the present invention is a distraction system fordistracting two adjacent vertebrae. Referring now to FIG. 20, FIG. 21and FIG. 22, there are shown, respectively, a lateral perspective viewof an introducer of the distraction system; a lateral perspective view(left) and a top perspective view (right) of one embodiment of a spacingcomponent of the distraction system; and a lateral perspective view(left) and a top perspective view (right) of another embodiment of aspacing component of the distraction system. As can be seen, thedistraction system 600 comprises an introducer 602 and a plurality ofspacing components 604, 606. The introducer 602 comprises a proximalinsertion portion 608 and a distal anchoring portion 610. The proximalinsertion portion 606 comprises a guidewire-type or tubular structure612. The distal anchoring portion 610 comprises a plurality of barbs614.

The distraction system 600 further comprises a plurality of stackable,deformable, spacing components 604, 606. Each spacing componentpreferably comprises a central opening 616 and a plurality of extensions618. In a preferred embodiment, each spacing component comprises threeextensions 618, as shown in FIG. 21. In another preferred embodiment,each spacing component comprises four extensions 618, as shown in FIG.22. The spacing components 604 are configured such that each extensionforms a curved shape to allow stacking of a plurality of spacingcomponents 604, 606 axially onto the introducer 602. In a preferredembodiment, each spacing component 604, 606 of the distraction system600 comprises a substance, such as shaped metal alloy, for examplenitinol, that has been processed to return to a shape suitable fordistracting two adjacent vertebral bodies as used in the method of thepresent invention. Further, each surface of the distraction system 600preferably has a polytetrafluoroethylene or other hydrophilic coating todecrease friction between components of the distraction system 600. Inanother embodiment, not shown, the spacing components can

In another embodiment, the present invention is another distractionsystem for distracting two adjacent vertebrae. Referring now to FIG. 23and FIG. 24, there are shown, respectively, a lateral perspective viewof another distraction system according to the present invention in theundeformed configuration; and a lateral perspective view of thedistraction system in the deformed configuration. As can be seen, thedistraction system 700 comprises a proximal connecting portion 702 and adistal distracting portion 704. The proximal connecting portion 702comprises a tubular structure comprising a solid band, a mesh orequivalent structure. The distal distracting portion 704 comprises aplurality of strips 706. Each strip is deformable from an extendedundeformed configuration to a curled deformed configuration. The strips706 are connected at their proximal end to the proximal connectingportion 702. Each strip 706 is preferably tapered from the proximal endto the distal end. In a preferred embodiment, each strip 706 tapers frombetween about 2.5 and 3 mm wide at the proximal end 708 to about 1 mmwide at the distal end 710, and tapers from about 1 mm thick at theproximal end 708 to between about 0.1 and 0.2 mm thick at the distal end710. The distraction system 700 comprises a substance, such as shapedmetal alloy, for example nitinol, that has been processed to return to ashape suitable for distracting two adjacent vertebral bodies as used inthe method of the present invention. Further, each surface of thedistraction system 700 preferably has a polytetrafluoroethylene or otherhydrophilic coating to decrease friction between components of thedistraction system 700.

The distraction system 700 can be made by any suitable method, as willbe understood by those with skill in the art with reference to thisdisclosure. In one embodiment, there is provided a method of making adistraction system, according to the present invention. In thisembodiment, the distraction system is made by, first, providing acylinder of biocompatible, shaped metal alloy, such as nitinol. Then, aplurality of axial cuts are made into the cylinder to produce aplurality of separated strips at the distal end of the hypotube. In aparticularly preferred embodiment, the cylinder is cut into three stripsat the distal end. The strips that are then bent into tight spirals andheat annealed to return to this shape when undeformed. In a preferredembodiment, the group of spirals when undeformed has a maximumtransverse profile of about 2 cm and a maximum axial profile of about 1cm. In another embodiment, the strips are disconnected from the proximalend of the cylinder and connected, such as by soldering, to a meshcylinder made of the same or equivalent material.

In another embodiment, the present invention is another distractionsystem for distracting two adjacent vertebrae. Referring now to FIG. 25,FIG. 26 and FIG. 27, there are shown, respectively, a lateralperspective view of the barbed plug of the distraction system accordingto the present invention in the deformed configuration (left) and in theundeformed configuration (right); a top perspective view (left) and alateral perspective view (right) of the rachet device of the distractionsystem in the deformed configuration; and a top perspective view (left)and a lateral perspective view (right) of the rachet device of thedistraction system in the undeformed configuration. As can be seen, thedistraction system 800 comprises a barbed plug 802, and comprises aratchet device 804. The barbed plug 802 comprises a cylindrical orconical central portion 806 and a plurality of barbs 808 distally. Whendeformed, FIG. 20-left, the barbs 808 of the barbed plug 802 contracttoward the axial center of the barbed plug 802. When undeformed, FIG. 25(right), the barbs 808 of the barbed plug 802 extend outward from theaxial center of the barbed plug 802. The barbed plug is formed from acone or cylinder that is cut axially to form the plurality of barbs andthen heat annealed to return to this shape. The ratchet device 804comprises a series of transversely separated strips 810 connected at oneend. The ratchet device is formed from a sheet that is cut transverselyinto a plurality of strips connected at one end of the sheet. The sheetis rolled axially and heat annealed to return to this shape. Whendeformed, FIG. 26 (left), the strips 810 are tightly coiled about thecentral axis of the ratchet device 804. When undeformed, FIG. 27(right), the strips 810 uncoil away from the central axis of the ratchetdevice 804. Each component of the distraction system 800 comprises asubstance, such as shaped metal alloy, for example nitinol, that hasbeen processed to return to a shape suitable for distracting twoadjacent vertebral bodies as used in the method of the presentinvention. Further, each surface of the distraction system 800preferably has a polytetrafluoroethylene or other hydrophilic coating todecrease friction between components of the distraction system 800.

In another embodiment, the present invention is a method of distractinga superior vertebra from an inferior vertebra using a distraction systemof the present invention. The method comprises, first, creating achamber is created within the intervertebral disk space between twoadjacent vertebrae. Next, a distraction system according to the presentinvention is provided and is placed within the chamber, therebydistracting the two adjacent vertebrae. In one embodiment, thedistraction system comprises an introducer comprising a proximalinsertion portion and a distal anchoring portion comprising a pluralityof barbs, and comprises a plurality of stackable, deformable spacingcomponents. In this embodiment, placing the distraction system withinthe chamber comprises advancing the introducer until the barbs encountercancellous bone in the superior portion of the distal vertebral body ofthe two adjacent vertebrae, inserting the plurality of spacingcomponents in their deformed configuration over the introducer into thechamber, and allowing the plurality of spacing components to expand totheir undeformed configuration. In another embodiment, the distractionsystem comprises a proximal connecting portion and a plurality of stripsconnected at their proximal end to the proximal connecting portion. Inthis embodiment, placing the distraction system within the chambercomprises advancing the distraction system into the chamber through achannel while the strips are in a straightened, deformed shape. Once inthe chamber, the strips return to their undeformed, spiral shape anddistract the two vertebral bodies axially. In another embodiment, thedistraction system comprises a barbed plug and a ratchet device. In thisembodiment, placing the distraction system within the chamber comprisesadvancing the barbed plug in the deformed configuration into the chamberthrough a channel, with either the barbs facing proximally or distally,until the barbed plug enter the chamber. The barbs of the barbed plugthen extend and contact cancellous bone in the superior portion of thedistal vertebral body of the two adjacent vertebrae or in the inferiorportion of the proximal vertebral body of the two adjacent vertebrae.Next, the ratchet device is advanced in the undeformed configurationthrough the channel and into the chamber and into the barbed plug. Oncein the chamber, each strip of the ratchet device expands axially toprevent retraction through the channel and sufficient length of theratchet device is advanced to cause the desired distraction of the twovertebrae. In a preferred embodiment, the distraction system isintroduced bilaterally. In a preferred embodiment, the method comprisesplacing the distraction system through a channel created through thepedicle of the superior vertebra. In another preferred embodiment, themethod additionally comprises placing the distraction system through asheath or hypotube, within a channel created through the pedicle of thesuperior vertebra.

The present invention further comprises a method for treating diseasesand conditions that change the spacial relationship between thevertebral bodies and the intervertebral disks, or that cause instabilityof the vertebral column, or both, and a method that allows the surgeonto access the intervertebral space to restore a more normalthree-dimensional configuration of the space, with or withoutadditionally fusing two adjacent vertebrae. Referring now to FIG. 28through FIG. 45, there are shown partial, cutaway, lateral perspectiveviews illustrating some aspects of the method as performed on a firstvertebral body 900 of a first vertebra 902, a second vertebral body 904of a second vertebra 906 and an intervertebral disk 908 between thefirst vertebral body 900 and second vertebral body 904.

In a preferred embodiment, the method comprises, first, selecting apatient who is suitable for undergoing the method. A suitable patienthas one or more than one change in the spacial relationship between afirst vertebral body of first a vertebra, a second vertebral body of asecond vertebra adjacent the first vertebral body, and an intervertebraldisk 908 between the first vertebral body and the second vertebral body,where the change in the spacial relationship is symptomatic, such ascausing pain, numbness, or loss of function, or where the change in thespacial relationship is causing real or potential instability, or acombination of the preceding, necessitating a restoration of a morenormal configuration or a change in the confirmation of the spacialrelationship between the first vertebral body and the second vertebralbody, or necessitating fusion of the first vertebra and the secondvertebra, or necessitating both. However, other diseases and conditionscan also be treated by the present methods, as will be understood bythose with skill in the art with reference to this disclosure. Among thediseases and conditions potentially suitable for treatment aredegenerated, herniated, or degenerated and herniated intervertebraldisks, degenerative scoliosis, disk or vertebral body infections, spaceoccupying lesions such as malignancies, spinal stenosis, spondylosis,spondylolisthesis, and vertebral instability, and injuries, includingvertebral fractures due to trauma or osteoporosis, and to surgicalmanipulations, that change the spacial relationship between thevertebral bodies and the intervertebral disks, causing pain, disabilityor both, and that cause instability of the vertebral column. While thepresent method is disclosed and shown with respect to the firstvertebral body 900 being superior to the second vertebral body 904, thepresent method can also be used with respect to a first vertebral body900 that is inferior to the second vertebral body 904, as will beunderstood by those with skill in the art with reference to thisdisclosure.

Next, transpedicular access to the first vertebral body 900 is obtainedpercutaneously, as shown in FIG. 28. In a preferred embodiment, thetranspedicular access is obtained by inserting a suitable gauge bonebiopsy needle 910, such as an 11-gauge bone biopsy needle (available,for example, from Parallax Medical, Scotts Valley, Calif. US; AllegianceHealth Care, McGaw Park, Ill. US; and Cook, Inc., Bloomington, Ind. US),through one pedicle of the first vertebra under suitable guidance, suchas fluoroscopic guidance. In a particularly preferred embodiment,transpedicular access is obtained bilaterally and the method disclosedin this disclosure is repeated bilaterally. Performance of the methodbilaterally allows greater removal of disk material, and thus, a largerintervertebral cavity for the deposition of bone matrix material. Then,a suitable gauge guidewire 912, such as a 1 mm diameter guidewire, isinserted into the first vertebral body 900 through the biopsy needle910, as shown in FIG. 28, and the biopsy needle 910 is removed leavingthe inserted guidewire 912.

Next, a suitable, non-flexible bone drill 914 is inserted over theguidewire 912, as shown in FIG. 29, and the non-flexible bone drill 914is actuated under guidance, thereby enlarging the channel created by thebiopsy needle 910 and guidewire 912 to approximately 4.5 mm in diameterand extending into approximately the posterior third of the firstvertebral body 900. In one embodiment, a straight drill sheath (notshown) such as a 0.25 mm thick, plastic tube having an outer diameter of5 mm is inserted over the guidewire 912 through the connective tissuesand musculature overlying the first vertebra 902 before inserting thestraight drill, and the straight drill is inserted over the guidewire912 but within the straight drill sheath. In this embodiment, thestraight drill sheath protects the connective tissues and musculature(not shown) overlying the first vertebra 902 from contact with thenon-flexible bone drill 914.

Next, the non-flexible bone drill 914 sheath is removed and, as can beseen in FIG. 30, replaced with a transpedicular working sheath 916 thatis inserted over the non-flexible bone drill 914 into the space createdby the non-flexible bone drill 914. The non-flexible bone drill 914 isremoved and a retainer tube 918 is advanced through the transpedicularworking sheath 916 until the distal tip of the retainer tube 918 exitsthe distal end of the transpedicular working sheath 916. Then, a firstflexible drill 920 is introduced through the entire length of theretainer tube 918. In a preferred embodiment, the retainer tube 918 is adevice according to the present invention. In another preferredembodiment, the flexible drill 920 is a device according to the presentinvention. As shown in FIG. 30, a flexible drill 920 is advanced throughthe proximal portion of the retainer tube 918 and out of the distalbeveled end of the retainer tube 918 causing the long axis of a flexibledrill 920 to make an approximately 90° angle with the long axis of theretainer tube 918. A flexible drill 920 is actuated, creating a channelthrough the first vertebral body 900 and into the intervertebral disk908 in a superior to inferior direction.

Next, the first flexible drill 920 is removed. In a preferredembodiment, a biocompatible guidewire (not shown), between about 0.4 mmand 1 mm in diameter, is then inserted through the pathway and into theintervertebral disk 908 to create a support structure, leaving thesupport structure and transpedicular working sheath 916.

In a preferred embodiment, a second flexible drill (not shown) accordingto the present invention, but with a drilling tip having a largercross-sectional diameter than the first flexible drill 920 is advancedthrough the transpedicular working sheath 916, and over the supportstructure if present. The second flexible drill is actuated, therebyenlarging the channel created by the first flexible drill 920 into theintervertebral disk 908. The final channel diameter, whether or not asecond flexible drill is used, is preferably between about 4 mm and 5 mmin diameter. The second flexible drill, if used, and the transpedicularworking sheath 916 are then withdrawn. If the remainder of the method isto be done using an over-the-wire technique, the support structure isleft in place, if it is used, as will be understood by those with skillin the art with reference to this disclosure. The Figures, however,depict the method using non-over-the-wire technique.

Next, as shown in FIG. 31, FIG. 32, FIG. 33 and FIG. 34, a flexiblesheath 922, such as a flexible braided or metal sheath, is advanced overthe support structure through the enlarged channel created by theflexible drill. Then, a cutting device 924 or an enucleation device 926,or an equivalent device, or more than one device sequentially, isadvanced through the flexible sheath 922 until the distal end of thecutting device 924 or the enucleation device 926 is within theintervertebral disk 908. In one embodiment, the cutting device 924 is adevice according to the present invention. In another embodiment, theenucleation device 926 is a device according to the present invention.The cutting device 924, if used, is then actuated as shown in FIG. 31,FIG. 32, FIG. 33 and FIG. 34, or the enucleation device 926, if used, isthen actuated as shown in FIG. 35 and FIG. 36, under suitable guidance,such as fluoroscopic guidance, removing a section of intervertebral disk908 material and, preferably, a portion of one or both endplatesdefining the intervertebral disk 908, preferably leaving cortical boneexposed on either the superior aspect 928 of the intervertebral disk908, the inferior aspect 930 of the intervertebral disk 908, orpreferably both the superior aspect 928 and the inferior aspect 930 ofthe intervertebral disk 908. In a preferred embodiment, the section ofendplate removed comprises about 2 cm in sagittal cross-section. In apreferred embodiment, the section of endplate removed comprises about30% of the endplate in sagittal cross-section. However, the annulusfibrosis is preferably preserved circumferentially. Then, the cuttingdevice 924 or enucleation device 926 is removed and the debris isremoved from the intervertebral disk 908 using suction, by flushing witha suitable solution such as saline, or by a combination of suction andflushing.

Next, as shown in FIG. 37 and FIG. 38, a fusion agent containment device932 is introduced into the empty space created by the cutting device 924or the enucleation device 926, or both, and deployed. In a preferredembodiment, as shown in FIG. 37 and FIG. 38, the fusion agentcontainment device 932 is a fusion agent containment device according tothe present invention. However, other fusion agent containment devicesare also suitable, as will be understood by those with skill in the artwith reference to this disclosure. In another preferred embodiment,introduction and deployment of the fusion agent containment device 932is accomplished by tightly coiling the fusion agent containment device932 within a deployment device comprising a flexible tube for containingthe coiled fusion agent containment device 932 and a central wire havinga discharge tip for pushing the coiled fusion agent containment device932 out of the flexible tube and into the empty space created by theenucleation device. Once in the empty space, the fusion agentcontainment device 932 returns to its unstressed shape, creating a linedchamber within the intervertebral disk 908. Next, the lined emptychamber is filled with a fusion agent, such as an agent comprisingcompatible bone matrix, thereby creating a boney fusion between thefirst vertebral body 900 and the second vertebral body 904. Suitablebone matrix, for example, is VITOSS™, available from Orthovita, Malvern,Pa. US and GRAFTON® Plus available from Osteotech, Inc., Eatontown, N.J.US, as well as demineralized cadaveric bone matrix material that hasbeen mixed with a bone morphogenetic protein, with or without thepatient's own bone marrow, to be both osteoconductive andosteoinductive.

In a preferred embodiment, as shown in FIG. 39, FIG. 40, FIG. 41, FIG.42, FIG. 43 and FIG. 44, the method further comprises introducing adistraction system 934, 936, 938 into the chamber, either before filingthe chamber with the fusion agent, or after filing the chamber with thefusion agent but before the fusion agent has set. Alternately, thechamber can be partially filled with a fusion agent, the distractionsystem 934, 936, 938 introduced before the fusion agent has set and anadditional fusion agent can be added to the chamber. The distractionsystem 934, 936, 938 can be any suitable structure, as will beunderstood by those with skill in the art with reference to thisdisclosure. In a preferred embodiment, the distraction system 934, 936,938 is a distraction system 934, 936, 938 according to the presentinvention. FIG. 31, FIG. 32, FIG. 33, FIG. 34, FIG. 35 and FIG. 36, showthree such distraction systems 934, 936, 938 being deployed. Thedistraction system 934, 936, 938 serves to distract, that is, toincrease axial separation of the first vertebra 902 from the secondvertebra.906, and to provide support for the deposited fusion material.

In a preferred embodiment, as shown in FIG. 45, the method furthercomprises performing an additional fusion procedure to join the firstvertebra 902 to the second vertebra 906. In one embodiment, as can beseen in FIG. 45, the additional fusion procedure comprises placingpedicle screws 940 into the transpedicular channel left from performingthe method of the present invention, and connecting the pedicle screws940 by spacing devices 942, as will be understood by those with skill inthe art with reference to this disclosure. However, any suitableadditional fusion procedure can be used, as will be understood by thosewith skill in the art with reference to this disclosure.

In a preferred embodiment, the method is performed on at least threeadjacent vertebral bodies and at the two intervertebral disks betweenthe at least three adjacent vertebral bodies by accessing the vertebralbodies and intervertebral disks, either unilaterally or bilaterally,transpedicularly at only one vertebral level. Each aspect of thisembodiment of the method corresponds to the equivalent aspect disclosedwith respect to performing the method on only two adjacent vertebrae andthe intervertebral disk between the two vertebrae, as will be understoodby those with skill in the art with reference to this disclosure.

Referring now to FIG. 46 through FIG. 54, there are shown partial,cutaway, lateral perspective views illustrating some aspects of thisembodiment of the method as performed on a first vertebral body 1000 ofa first vertebra 1002, a second vertebral body 1004 of a second vertebra1006, an intervertebral disk 1008 between the first vertebral body 1000and second vertebral body 1004, a third vertebral body 1010 of a thirdvertebra 1012 and an intervertebral disk 1014 between the secondvertebral body 1004 and third vertebral body 1010. As can be seen, afterselecting a suitable patient, transpedicular access to the firstvertebral body 1000 is obtained percutaneously and a non-flexible bonedrill is used to access the intervertebral disk 1008 between the firstvertebral body 1000 and the second vertebral body 1004 substantially asdisclosed above. However, in this embodiment, a flexible drill 1016 isused to continue making a channel completely through the intervertebraldisk 1008 between the first vertebra 1002 and second vertebral body1004, FIG. 46, through the second vertebral body 1004 and into theintervertebral disk 1008 between the second vertebral body 1004 and thethird vertebral body 1010, FIG. 47. Next, the intervertebral disk 1008between the second vertebral body 1004 and the third vertebral body1010, as well as a portion of the inferior endplate 1018 of the secondvertebral body 1004 and the superior endplate 1020 of the thirdvertebral body 1010, are removed using a cutting device (not shown) oran enucleation device 1022 or both, or an equivalent device, FIG. 48 andFIG. 49. Then, a fusion agent containing device 1024 is deployed intothe intervertebral 1014 between the second vertebral body 1004 and thethird vertebral body 1010 and in the intervertebral disk 1008 betweenthe first vertebral body 1000 and the second vertebral body 1004, FIG.50. In a preferred embodiment, a distraction system 1026 is placedwithin the fusion agent containing device 1024 in both theintervertebral disk 1008 between the first vertebra 1002 and secondvertebral body 1004, and the intervertebral disk 1008 between the secondvertebral body 1004 and the third vertebral body 1010, FIG. 51, FIG. 52,FIG. 53 and FIG. 54. Next, each fusion agent containing device 1024 isfilled with fusion agent, thereby fusing the first vertebra 1002 to thesecond vertebra 1006, and fusing the second vertebra 1006 to the thirdvertebra.

Additionally, in a preferred embodiment, (not shown), an additionalfusion procedure can be performed to join the first vertebra 1002 withthe second vertebra 1006, to join the second vertebra 1006 with thethird vertebra, or both, in a manner corresponding to FIG. 45.

Although the present invention has been discussed in considerable detailwith reference to certain preferred embodiments, other embodiments arepossible. Therefore, the scope of the appended claims should not belimited to the description of preferred embodiments contained in thisdisclosure. All references cited herein are incorporated by reference totheir entirety.

1. A flexible drill comprising a lower sub-assembly connected to anupper sub-assembly; where the lower sub-assembly comprises a spin luerlock, a retainer tube, a piston anchor, a piston level, a piston, adistal O-ring and a proximal O-ring; and where the upper sub-assemblycomprises a drilling tip, guiding tube, a barrel knob, a barrel, athreaded adapter, a liner, a bearing housing, a flexible shaft, a distalbearing, a proximal bearing, a collet, a bearing cap and a motorreceptacle; where the guiding tube comprising a proximal segment havinga central axis and a distal segment having a distal end; where thedrilling tip is connected to the distal end of the distal segment; andwhere the guiding tube comprises a substance that has been processed toreturn to a shape where the distal segment has a radius of curvaturesufficient to cause the drilling tip at the end of the distal segment toorient at between about 10° and 150° off of the central axis of theproximal segment when the guiding tube is not subject to distortion. 2.The flexible drill of claim 1, where the lower sub-assembly furthercomprises a spin luer lock, a piston anchor, a piston level, a piston, adistal O-ring and a proximal O-ring; and where the upper sub assemblyfurther comprises the drilling tip, a barrel knob, a barrel, a threadedadapter, a liner, a bearing housing, a flexible shaft, a distal bearing,a proximal bearing, a collet, a bearing cap and a motor receptacle. 3.The flexible drill of claim 1, further comprising a guiding tip attachedto the drilling tip.
 4. The flexible drill of claim 1, furthercomprising an axial channel for accepting a guide wire.
 5. A method ofdrilling a material, comprising: a) providing a drill according to claim1; b) advancing the flexible drill under distortion into the material;c) removing the distortion from the flexible drill; and d) actuating theflexible drill.
 6. The method of claim 5, further comprising passing aguide wire through the flexible drill before actuating the flexibledrill, after actuating the flexible drill, or both before and afteractuating the flexible drill.
 7. The method of claim 5, where thematerial to be drilled is selected from the group consisting of bone,cartilage and intervertebral disk.